# Running engines at half throttle??



## blkcloud (Apr 7, 2016)

I hate hi jacking threads.. but.. talking about running air cooled engines at half throttle.. I have always been told by small engine mechanics that, the faster one runs, the cooler it is.. on guy was replacing a garden tiller engine a elderly lady had because it overheated.. he said she would never run it full throttle and it burned its self up..


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## Woos31 (Apr 7, 2016)

I was taught for saws anyway to run WFO, as they were engineered to run full throttle. My ole man used to and still does to this day through sh*t at me if he thinks I'm holding back on a saw lol


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## Stihlbillie (Apr 7, 2016)

Also half throttle causes massive carbon buildup


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## Sandhill Crane (Apr 7, 2016)

I have a DR chipper I found last year on Craigslist. 18 hp Briggs that is fifteen years old. No throttle, never had one, and runs wide open. I like to throttle stuff down before shutting it off. Can't with this. There is a manual choke, that's it. The one thing I do not run wide open is the SuperSplit. Rack and pinion seems to mesh better at three quarter plus throttle. I have a Ford that's becoming air cooled from rust holes, but no, not wide open.


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## Sawyer Rob (Apr 7, 2016)

blkcloud said:


> I have always been told by small engine mechanics that, the faster one runs, the cooler it is.. on guy was replacing a garden tiller engine a elderly lady had because it overheated.. he said she would never run it full throttle and it burned its self up..



I'd only way I'd believe "that" was the cause, is IF the engine was over loaded (read too small for the job) in the first place.

They make less hp at half throttle and that probably put that motor in "over load" condition...

SR


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## Sawyer Rob (Apr 7, 2016)

Stihlbillie said:


> Also half throttle causes massive carbon buildup


 Not in a small 4-stroke though...

SR


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## rarefish383 (Apr 7, 2016)

Run all of my small engines wide open, Joe.


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## Stihlbillie (Apr 7, 2016)

Sawyer Rob said:


> Not in a small 4-stroke though...
> 
> SR


Not true, any engine that uses gasoline has carbon in the exhaust gases, this is why you need to "get on it" every once in a while.


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## NSMaple1 (Apr 7, 2016)

I vary mine with the load. The more load, the more throttle. Splitting small wood = part throttle. Big or gnarly wood = give 'er.

The build up would come down to how good (or bad) the carb jetting is. If you have to open it up to clean it out, it's jetted too fat in the low to mid. Which you may or may not be able to do anything about, depending on the carb.


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## greenskeeper (Apr 7, 2016)

NSMaple1 said:


> I vary mine with the load. The more load, the more throttle. Splitting small wood = part throttle. Big or gnarly wood = give 'er.



Exactly my strategy as well. Normal splitting is about 3/10ths throttle until something gnarly needs that extra power....push it to "eleven"


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## homemade (Apr 7, 2016)

NSMaple1 said:


> I vary mine with the load. The more load, the more throttle. Splitting small wood = part throttle. Big or gnarly wood = give 'er.




I am not a fan of this method. I run the saw at full throttle and only put half of the push in the saw. I feel I can control the cutting speed better and not bounce off the ground or off my limbs. Granted if the branch is small, it might only take an one second blip with the throttle to get threw it, but never half throttle.


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## JeffHK454 (Apr 7, 2016)

My splitter took a bad tumble years back and ever since then the 9hp Tecumseh has had no governor , choke or any type of throttle linkage ..it gets started then ran at one RPM till I'm done or it runs out of gas. Once I get it running I jamb some splitter scraps under what's left of the throttle shaft and off I go, I even have to use ether every time I start it! 

I traded some firewood for a nice electric start comercial Lp Honda motor because I figured the abuse I was heaping on the origional would be the death of it ...ten years later I've split 80+ cord running WFO!


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## cantoo (Apr 7, 2016)

I run mine wide open or very close to it. I have a Walker mower and run synthetic in it to keep it a bot cooler. We also run Bobcats and they run wide open too. We replace engine but I doubt that it's from running wide open.
I would think it would be pretty easy to do a test on your engine using a temp gauge at different throttle settings.


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## NSMaple1 (Apr 7, 2016)

homemade said:


> I am not a fan of this method. I run the saw at full throttle and only put half of the push in the saw. I feel I can control the cutting speed better and not bounce off the ground or off my limbs. Granted if the branch is small, it might only take an one second blip with the throttle to get threw it, but never half throttle.



Yes, with a saw. Me too. Chain speed counts there.


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## logeeland (Apr 7, 2016)

Idle or half throttle on a 2 stroke does more harm then good. Does not let the fuel get hot enough to burn correctly. On a 4 stroke air cooled I have seen no difference. My tractors run at idle and mid throttle a lot.


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## Sawyer Rob (Apr 7, 2016)

Stihlbillie said:


> Not true, any engine that uses gasoline has carbon in the exhaust gases, this is why you need to "get on it" every once in a while.


 In a small 4-stroke that is running "properly", it would take nearly forever for it to happen!

SR


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## bikemike (Apr 7, 2016)

blkcloud said:


> I hate hi jacking threads.. but.. talking about running air cooled engines at half throttle.. I have always been told by small engine mechanics that, the faster one runs, the cooler it is.. on guy was replacing a garden tiller engine a elderly lady had because it overheated.. he said she would never run it full throttle and it burned its self up..


That more depends on tuning and how hard they are working.


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## c5rulz (Apr 8, 2016)

Since it is almost always cold when running the spitter, 20 - 40 degrees it will not run hot, far from it. I always split by myself and it is not doing anything while I stack the splits so I run it at about 80% and a tank of fuel lasts over 3 hours. If anything hydro oil gets hot the fast it is circulated as outside temps go up.


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## bikemike (Apr 8, 2016)

My daddy said " if the valves aren't floating run it harder.

Life is like a log splitter.when it's dead so are you


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## ckr74 (Apr 8, 2016)

If the engine is not under a constant heavy load it's ok to throttle them back. Less fuel and less noise.


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## brenndatomu (Apr 8, 2016)

Boy the BS is getting deep in this thread!
If an engine blows up at half throttle, then something else was wrong. It won't over heat from half throttle, less speed = less fuel/less work = less heat to dissipate.
If an engine bogs at half throttle, give it more throttle.
If a tool/machine works best at full throttle, run it there, if not, then don't.
Bout all I got to say about that...


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## bikemike (Apr 8, 2016)

Yep tune and timing and bad oil is the factors of overheating sometimes valve lash too


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## ckr74 (Apr 8, 2016)

Agreed. Neglect comes to mind when a motor fails. Usually not always.


brenndatomu said:


> Boy the BS is getting deep in this thread!
> If an engine blows up at half throttle, then something else was wrong. It won't over heat from half throttle, less speed = less fuel/less work = less heat to dissipate.
> If an engine bogs at half throttle, give it more throttle.
> If a tool/machine works best at full throttle, run it there, if not, then don't.
> Bout all I got to say about that...





bikemike said:


> Yep tune and timing and bad oil is the factors of overheating sometimes valve lash too


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## bikemike (Apr 8, 2016)

I've seen lots of stuff pass through my hands that never had a oil change just keep adding oil or sometimes and flooding carb can kill the oil but yet it still looks like oil


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## c5rulz (Apr 8, 2016)

ckr74 said:


> If the engine is not under a constant heavy load it's ok to throttle them back. Less fuel and less noise.




Exactly my thoughts.

I have the rounds stacked on pallets, they come off the pallet to the splitter 3- 4' away and the splits are stacked immediately. Slightly more time consuming but the wood is only handled once. Hence the splitter is not in constant use.


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## Sawyer Rob (Apr 8, 2016)

c5rulz said:


> Exactly my thoughts.
> I have the rounds stacked on pallets, they come off the pallet to the splitter 3- 4' away and the splits are stacked immediately. Slightly more time consuming but the wood is only handled once. Hence the splitter is not in constant use.


 The wood is "only handled once"?? How do the rounds get on the pallet? Then it has to get to the stove too... lol

SR


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## c5rulz (Apr 8, 2016)

Sawyer Rob said:


> The wood is "only handled once"?? How do the rounds get on the pallet? Then it has to get to the stove too... lol
> 
> SR




People buy it, the stack is measured and marked and they haul it themselves.


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## Sawyer Rob (Apr 8, 2016)

So, YOU buy the rounds on a pallet, split it and put it back on a pallet? Cause, putting the rounds on a pallet is handling it one time, then splitting it, is handling it a second time... And, some would say taking it off the splitter and putting the splits on a pallet is handling it a third time...

SR


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## Brushwacker (Apr 8, 2016)

Stihlbillie said:


> Also half throttle causes massive carbon buildup


I am not an expert myself, but from what I was told in my early days with motorcycles by an expert ( pro road racer and short track-motorcycle dealer) as long as the engine was under load it would burn cleaner, and hottest was when letting off the throttle which I at least once experienced seizure when letting off myself. I was with the understanding the richest burning was wide open not under load.


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## Brushwacker (Apr 8, 2016)

Deep in the cuts I aim to keep wide open, nearing the end I feather the throttle to control the shape and effect of the hinge. If to much wood is holding I may gun her , bucking I slow down coming out of the cut for control reasons. No problems with carbon or overheating the way I use mine. tune and maintainence is most my concern.


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## Scablands (Apr 8, 2016)

I'm fairly certain the engine itself isn't the issue, it's primarily the centrifugal clutch. Saw manufacturers want the engine at full RPM during cutting to ensure that the clutch isn't slipping on the rim. The heat buildup from a slipping clutch will certainly damage a saw.


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## kingOFgEEEks (Apr 8, 2016)

Also remember - with a saw, the fuel carries the lubrication for the engine with it, so since the carb is calibrated to be either WOT or idle, so you have to give it the beans.

4 cycle *** doesn't have this issue, so partial throttle is ok, and is a lot quieter. I run my splitter at 2/3-3/4 throttle for easier splitting stuff, and it sips fuel, but when I get into the gnarly stuff, I open it up all the way.


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## kingOFgEEEks (Apr 8, 2016)

*** = outdoor power equipment. Darn filter.


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## c5rulz (Apr 8, 2016)

Sawyer Rob said:


> So, YOU buy the rounds on a pallet, split it and put it back on a pallet? Cause, putting the rounds on a pallet is handling it one time, then splitting it, is handling it a second time... And, some would say taking it off the splitter and putting the splits on a pallet is handling it a third time...
> 
> SR




Rounds are unloaded from a trailer to the pallets when it is parked within 2'. The splittter is pulled up very close to the stacked rounds, then split and restacked. I am just an old retired guy who plods along.
Note the makeshift log table.
Here you'll get the idea:


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## ckr74 (Apr 8, 2016)

c5rulz said:


> I am just an old retired guy who plods along.


 You don't do bad for old feller.


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## c5rulz (Apr 8, 2016)

ckr74 said:


> You don't do bad for old feller.




Trust me when I tell you that the amount of movement is kept to a minimum. I cut up a lot of log cut offs and when my logger buddies are in town I don't load the trailer either, this takes about 3 min.











If it's real big, just cut into rounds and roll into trailer. Always park within 3' of the pile. Note, always take the hardwood and not some of the crap in this pile.


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## Whitespider (Apr 8, 2016)

brenndatomu said:


> *Boy the BS is getting deep in this thread!*


No BS...

Running a small, air-cooled, non-pressure lubed, 4-cycle engine at anything short of full throttle is detrimental to its health... and because of the governor setup, it will often actually use more fuel, not less. Small, splash-lubed, air-cooled, 4-cycle engines are designed to run at full throttle... that's when lubrication and cooling air flow is optimized. When running at ½ throttle, horsepower and torque is drastically reduced, causing it to lose a greater _percentage_ of RPMs when load is applied... which causes the governor to _fully_ _open_ the throttle sooner and for a longer period for recovery... which means more fuel and more heat while at the same time receiving less lubrication and cooling air flow.

Small, splash-lubed, air-cooled, 4-cycle engines should always be run a full throttle (approximately 3400-3600 RPMs depending on model) whenever any load is applied... no matter how small the load. Anything less than full throttle is causing unnecessary wear and damage... and likely even using more fuel. (Keep in mind that "full throttle" is not "wide open" with the governor setup on a 4-cycle.)

No BS... seriously... no BS...
*


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## WoodTick007 (Apr 8, 2016)

Whitespider said:


> No BS...
> 
> Running a small, air-cooled, non-pressure lubed, 4-cycle engine at anything short of full throttle is detrimental to its health... and because of the governor setup, it will often actually use more fuel, not less. Small, splash-lubed, air-cooled, 4-cycle engines are designed to run at full throttle... that's when lubrication and cooling air flow is optimized. When running at ½ throttle, horsepower and torque is drastically reduced, causing it to lose a greater _percentage_ of RPMs when load is applied... which causes the governor to _fully_ _open_ the throttle sooner and for a longer period for recovery... which means more fuel and more heat while at the same time receiving less lubrication and cooling air flow.
> 
> ...


Well that is all fine and good. . . but what about the increased noise and fuel consumption? I always idle my engines for the environment and children.


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## johnnylabguy (Apr 8, 2016)

My TSC husky splitter manual actually advises to run the splitter at full throttle. But I must admit that if I don't have hearing protection on I usually run 3/4. But if the work tunes muffs are on it's WFO. But thats mainly because when I run a tankful it's Miller time. Random thought... I split mostly by hand now and in between rounds I often re-hydrate... no wonder I enjoy hand splitting so much...

When it comes to saws a properly tuned two-stroke is made to make power best wide open. The chainsaw forum would have fun with any half throttle suggestions.


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## 7sleeper (Apr 9, 2016)

As mentioned by others BS is pretty high here.


Stihlbillie said:


> Also half throttle causes massive carbon buildup


That is just not correct. It takes quite some time for carbon to build up in an engine. Further running the engine at WOT, when the carb is correctly set, usually takes care of any carbon builld up. As mentioned above already by others, carbon build up is MUCH MORE a problem of NOT correct carb settings or BAD fuel or TOO much oil in your mix.


logeeland said:


> Idle or half throttle on a 2 stroke does more harm then good. *Does not let the fuel get hot enough to burn correctly*. ....


Sorry but this is NOT correct! Fuel temperatures has hardly anything to do with gas burning correctly.

7


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## Whitespider (Apr 9, 2016)

WoodTick007 said:


> *Well that is all fine and good. . . but what about the increased noise and fuel consumption? I always idle my engines for the environment and children.*


Idling an engine off-load is not a problem... my whole post was about running it on-load... and I addressed fuel consumption.
*


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## WoodTick007 (Apr 9, 2016)

Whitespider said:


> Idling an engine off-load is not a problem... my whole post was about running it on-load... and I addressed fuel consumption.
> *


What about the ozone and the environment and the oceans and the children? Hmmm? Hmmmm, Mr Spider?


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## abbott295 (Apr 9, 2016)

That's when you need to be sure you have bias-ply tires on it.


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## greenskeeper (Apr 9, 2016)

Whitespider said:


> No BS...
> 
> Running a small, air-cooled, non-pressure lubed, 4-cycle engine at anything short of full throttle is detrimental to its health... and because of the governor setup, it will often actually use more fuel, not less. Small, splash-lubed, air-cooled, 4-cycle engines are designed to run at full throttle... that's when lubrication and cooling air flow is optimized. When running at ½ throttle, horsepower and torque is drastically reduced, causing it to lose a greater _percentage_ of RPMs when load is applied... which causes the governor to _fully_ _open_ the throttle sooner and for a longer period for recovery... which means more fuel and more heat while at the same time receiving less lubrication and cooling air flow.
> 
> ...



I should send my log splitter engine out for a scientific study then. Going on 16 years running almost entirely at 1/3 throttle for hours on end. Every application is different.


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## brenndatomu (Apr 9, 2016)

Whitespider said:


> 4-cycle engines should always be run a full throttle (approximately 3400-3600 RPMs depending on model) whenever any load is applied... no matter how small the load


Naw, ain't buyin it. I been running my small engines at 1/2 - 3/4 throttle (mostly) for ~30 years (+) now, ain't blowed one up yet. I try not to run the bag off any of my equipment and it seems that things last much longer for me than the average Joe. And my log splitter uses much less fuel run 1/2 -2/3 throttle that than if I go full bore. It gets thirsty at 3600 RPM.
I'm not saying that engines should always be run at something less than full throttle, just that they _can be_ if you use some common sense and kinda match speed to load. Sometimes WFO is called for, like 20" bar buried in a 24" log...


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## Whitespider (Apr 9, 2016)

WoodTick007 said:


> *What about the ozone and the environment and the oceans and the children? Hmmm? Hmmmm, Mr Spider?*


The topic was small engines... not environmentalism.

How many times do I have to say it?? Running a small, splash-lubed, air-cooled, 4-cycle engine at less than full throttle (under load) will often cause it to use more fuel, not less. It also causes the governor to _fully_ _open_ the throttle for a greater percentage of the time.

Now, use your head for a second... if it's using more fuel overall and/or _fully_ _opening_ the throttle more of the time... wouldn't that mean more emissions?? If your goal is to reduce emissions, then the best way to do that would be to run the engine at a speed (RPM) that produces the optimum ratio of power to fuel consumption... which is full throttle. If you believe running a small, splash-lubed, air-cooled, 4-cycle engine at less than full throttle (under load) is better for the environment... you're delusional.
A small, splash-lubed, air-cooled, 4-cycle engine runs at peak efficiency at full throttle (3400-3600 RPM)... peak efficiency is the key to reducing emissions, not engine speed. You're not using your head...

And just so you know... I don't buy into the environmental extremism.
I believe in common sense... not extremism...
I'm not adjusting how I use a small engine because of some ridiculous notion it saves the environment, but I will keep the engine properly tuned so it runs a peak efficiency... which is good for me, good for the engine, and good for the environment.



greenskeeper said:


> *I should send my log splitter engine out for a scientific study then. Going on 16 years running almost entirely at 1/3 throttle for hours on end. Every application is different.*


No... the application of load on a small, splash-lubed, air-cooled, 4-cycle engine is the application of load... not different applications.
The work being done may be a different application of the load... but the effect the load has on the the engine is still the same.

Keep in mind, a log splitter engine is under load for a tiny amount of time over a 16 year period when compared to, say, a lawn tractor maintaining 3, 4 or 5 acres of grass. Heck, for that matter, total run time is typically a lot less... a whole lot less. My log splitter is over 35 years old now... but I've been through several grass cutting machine engines during that time.

Just because your engine ain't broken don't mean you ain't running it in a way that causes unnecessary wear and damage... which is all I said. I didn't say it would break in 16 years... or 10... or 5... or 50. Small, splash-lubed, air-cooled, 4-cycle engine engines wear out mostly because of run time under load... but there is a way to reduce the effects of run time under load... it's called full throttle (clean oil also helps a lot).
*


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## Whitespider (Apr 9, 2016)

brenndatomu said:


> *Naw, ain't buyin it. I been running my small engines at 1/2 - 3/4 throttle (mostly) for ~30 years (+) now, ain't blowed one up yet.*


Than don't buy it (shrug)... but see the above post, just because you ain't "blowed one up" don't mean sour owl squat 
Heck, I wasn't even talking about blowing up... a brand spankin' new engine can "blow up" for many reasons.
Also, keep in mind, small "pressure lubed" engines (they have oil filters on them) are not what I'm talking about... that's a different animal.
*


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## Sawyer Rob (Apr 9, 2016)

What it boils down to is, how much load is on the motor...

Sure, if it's "heavily" loaded for the hp, that's not good, but it it's making "enough" hp at "part throttle", running it that way absolutely saves fuel, it also makes "less" heat and is no problem for that motor at all!

Now, I'm NOT talking about chainsaws here...

SR


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## Whitespider (Apr 9, 2016)

Sawyer Rob said:


> *..."part throttle", running it that way absolutely saves fuel, it also makes "less" heat...*


You're not looking at the complete picture.
Heat is generated more by the fuel burned than friction... and heat is regulated by the cooling air flow.

When load is applied to a small, splash-lubed, air-cooled, 4-cycle engine the RPMs drop... which causes the governor to to open the throttle to _wide_ _open_ position. It don't matter where you set the throttle control (it's actually a governor control)... it's the governor that controls the actual throttle... and when RPMs drop under load, the throttle goes _wide_ _open_ no matter where you've set that throttle control. When the engine is running at less than the full throttle (setting) the engine loses a greater _percentage_ of RPMs when load is applied... which causes the actual throttle (controlled by the governor) to go _wide_ _open_ _*sooner*_, and stay that way _*longer*_ to recover RPMs (because HP and torque are reduced).

There ain't no magic to remove the physics... when the governor causes _wide_ _open_ throttle under load it means more fuel... which means more heat... while, at the same time, the lower RPMs (because of your throttle setting) are moving less cooling air past the engine, and less lubrication is being delivered (splashed) to the friction parts. A small, splash-lubed, air-cooled, 4-cycle engine does not run cooler at "part throttle" under load... it will actually run hotter. In truth... the fastest, most efficient way to cool a small, splash-lubed, air-cooled, 4-cycle engine is to run it at _full_ _throttle_ _off-load_ because cooling air flow and lubrication is optimized.

However, a log splitter engine is not under continuous load like, for example, a grass cutting machine... so the effect ain't as great, but it's still there.
*


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## JeffHK454 (Apr 9, 2016)

There's no debating that splash-lubed engines are designed to be run at full throttle..it takes a certain RPM to sling the oil where it needs to be. I run mine at full throttle because it's where the hydraulic pump makes its full flow rating and I get the most work out of my splitter.

My objective is to get the splitting done so I can go fishing or offroading..fun to me isn't listing to a splitter putt along all day at 1/3 throttle to save $3 worth a gas.


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## brenndatomu (Apr 9, 2016)

Whitespider said:


> Heck, I wasn't even talking about blowing up...


OP was...


blkcloud said:


> guy was replacing a garden tiller engine a elderly lady had because it overheated.. he said she would never run it full throttle and it burned its self up..





Whitespider said:


> and when RPMs drop under load, the throttle goes _wide_ _open_ no matter where you've set that throttle control.


Exactly...don't matter if the throttle is WFO or 1/2. But when set at 1/2, it is shooting at 1800(ish) RPM and that means less fuel intake strokes...so less fuel used. Then once the load is removed (log splitter) my 1/2 throttle engine needs less fuel to supply its 1800 RPM (while it is waiting on me to load the next log) than yours screaming away at 3600 the whole time


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## brenndatomu (Apr 9, 2016)

JeffHK454 said:


> There's no debating that splash-lubed engines are designed to be run at full throttle..it takes a certain RPM to sling the oil where it needs to be


If that were true then no small engine would have a throttle...just set at 3600 permanently, like some of the cheap push mowers are now.
I have never seen any small engine manual that says "never use the throttle in any position other than full, because it gon blow up if you do"


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## brenndatomu (Apr 9, 2016)

JeffHK454 said:


> I run mine at full throttle because it's where the hydraulic pump makes its full flow rating and I get the most work out of my splitter.


There is some argument for full throttle here. On some hydraulics you just need the RPM to make things work well.
But on my splitter, it only makes ~1 second difference between 1/2-2/3 throttle VS full, and that it if I do a FULL stroke (out and back) which doesn't happen much. So thats less than 1 second per stroke lost, meh, who cares, I'm rarely in that big of a hurry. I prefer the less noise 1/2 throttle setting...but that's just me, each to their own. And 'bout the only time I run my mower full tilt is if it starts raining and I'm almost done...then ZOOM! (all 8MPH of ZOOM )


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## JeffHK454 (Apr 9, 2016)

brenndatomu said:


> If that were true then no small engine would have a throttle...just set at 3600 permanently, like some of the cheap push mowers are now.
> I have never seen any small engine manual that says "never use the throttle in any position other than full, because it gon blow up if you do"



Who in this thread is saying it's gonna "blow up" ?

I'm saying that the people that design and build these types of engines recommend for peak performance and longevity that they be run at full throttle. This thread is a perfect example of why manufacturers have started taking throttles off equipment ..to keep people who think they're smarter than they really are from running equipment at part throttle , hurting effiency and durability.

My crappy old SpeeCo is slow enough at WFO ..1/3 throttle I'd still be splitting 2014's wood..


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## Whitespider (Apr 9, 2016)

brenndatomu said:


> *Then once the load is removed (log splitter) my 1/2 throttle engine needs less fuel to supply its 1800 RPM (while it is waiting on me to load the next log) than yours screaming away at 3600 the whole time*


*Ha‼*
My log splitter has an auto-throttle control; it goes to full throttle whenever the ram is moving (when the engine is on-load), and automatically goes to idle when the ram is not moving (when the engine is off-load).



brenndatomu said:


> *If that were true then no small engine would have a throttle...just set at 3600 permanently...*


Many new engines are set up exactly that way... see the quote below.
The (user) throttle control was never intended to be used as anything except a way to go from full-throttle to idle, and back again. The sliding cable/lever design was just the simplest, easiest, and least expensive way to accomplish that... and incorporate the on/off and choke controls into the same control lever on many. Read nearly any owner/user manual and it will tell you to _always_ run your small, splash-lubed, air-cooled, 4-cycle engine at full throttle when on-load (most pressure-lubed as well).



JeffHK454 said:


> *This tread is a perfect example of why manufacturers have started taking throttles off equipment ..to keep people who think they're smarter than they really are from running equipment at part throttle , hurting effiency and durability.*


There's one-hell-of-a-lot of truth in that... although the EPA has also pushed for it because of the efficiency aspect (which effects emissions... take note WoodTick007).
I have four pieces of (relatively newer) equipment set up that way now ... my generator, my push mower, my snow thrower, and my pressure washer. They have an on/off control switch, a separate choke or primer control, but no throttle control whatsoever... 3600 RPMs or nothing. I really miss the ability to idle them down off-load (generator ain't a big deal)... but as you said, people think they're smarter than they really are, and now we all have to live with being protected from ourselves because of it.
*


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## greenskeeper (Apr 9, 2016)

unless you are lugging the engine, any throttle setting is ok to get the job done. If my splitter has a 6hp engine at 3600rpm or whatever and I can split wood at 1/3 throttle or say 2hp without lugging then there is no harm being done, less noise, less wear, less fuel consumed.


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## brenndatomu (Apr 9, 2016)

Whitespider said:


> least expensive


Now _thats_ why some of these newer engines have no speed control, that and there is no reason for speed control on a genny for example, since 3600 is needed to set 60 HZ. Speaking of HZ, I dunno how they set a genny for 50HZ (where they use that)...surely they don't slow the engine down to 3000...
Not to mention that 3600 RPM all its life will wear it out faster...so its win/win for the mfgrs to set throttle for WFO all the time


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## Joesell (Apr 9, 2016)

I can see why you might run a Supersplit at 3/4 throttle to help with the gear mesh. 

However, I dont understand why you would run a hydro splitter at anything less the WFO. The hydro pump is set to run at max output at 3600rpm. Running it slower doesn't change the psi, it only changes the speed of the ram. 

Splitting wood is a chore, not something I do for fun. Why would I want to stand there and watch the ram move any slower then it has to. Not only that, but people spend crazy amounts of money to shave a few seconds off the cycle time. 

I guess adding seconds is free. Some people can't resist a freebie.


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## JeffHK454 (Apr 9, 2016)

Joesell said:


> I can see why you might run a Supersplit at 3/4 throttle to help with the gear mesh.
> 
> However, I dont understand why you would run a hydro splitter at anything less the WFO. The hydro pump is set to run at max output at 3600rpm. Running it slower doesn't change the psi, it only changes the speed of the ram.
> 
> ...



Exactly !


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## Sawyer Rob (Apr 10, 2016)

I don't run my splitter wide open, it goes fast enough without it, I'm old and getting slower, I don't need to go any faster! lol

Also, there's LESS noise, it uses less fuel too, but then again, I'm not running an under powered splitter either, or one with a splash oil system...

AT LEAST that's been MY experience...

SR


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## NSMaple1 (Apr 10, 2016)

With the exception of my 3200w generator, all of my splash-lubed, air-cooled, 4-cycle engines have variable throttle settings. I set them to the RPMs that match the load I am putting on them, and also take into account how fast I am wanting to or able to work. I run my splitter at full throttle to match the wood it's splitting, not how fast I can go - even at half throttle, it's usually waiting for me, rather than the other way around. Never any engine issues. Even on the many B&S powered 2" water pumps we've had over the years - run the trottle up some filling, less than half emptying. They have pumped millions of gallons over the years

Should bring this up at the go-cart rental track sometime. That would be fun watching the first-timers through the turns...


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## Whitespider (Apr 10, 2016)

brenndatomu said:


> *...I dunno how they set a genny for 50HZ (where they use that)...surely they don't slow the engine down to 3000...*


That's not the got'cha you think it is... nearly all engine manufactures make "special purpose" models for such applications.
The 24 HP Kohler on my lawn tractor runs at 3300 _maximum_ RPM... that's the specification... by design, that's where that particular engine develops maximum HP and torque... 3300 RPM is full throttle on that model... the engine is designed to run full throttle.
The Briggs on dad's old pressure washer runs at 3060 _maximum_ RPM... that's the specification... by design, that's where that particular engine develops maximum HP and torque... 3060 RPM is full throttle on that model... the engine is designed to run full throttle.
Many engines on new push lawn mowers are designed to run at 3200 RPM... necessary to comply with blade tip speed and projectile safety laws.
3600 RPMs is the basic (actually because of the 60HZ deal)... but it ain't a law... and you can buy special purpose engines designed to run as slow as 2000 RPM maximum specification.
*


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## Mad Professor (Apr 10, 2016)

If you have older equipment it was designed to run slow rpm. A farmer I worked for would slap you up the head if you revved his tractor, tillers, garden tractors.

I can concur with this. If it bogs I use a lower gear.

I have a 1940 ford 9N, 1972 Ford 2000 gas, 1973 Ford lgt 145 (k321 motor) and 1972 troy built horse tiller (tecumseh H60). They all have original internals except the 9N, it had a valve job. None even smoke, knock or use oil. And they get worked every year, with regular oil changes, filters, and upkeep.

Chainsaws and newer stuff built overseas are a different story.

P.S. my uncle had an old chevy 6 that seldom went over 50 mph, it had over 300,000 on it when he scrapped it due to body rot.


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## c5rulz (Apr 10, 2016)

Whitespider said:


> *Ha‼*
> My log splitter has an auto-throttle control; it goes to full throttle whenever the ram is moving (when the engine is on-load), and automatically goes to idle when the ram is not moving (when the engine is off-load).



S0unds like a great feature.

So, isn't your splitter then running at less than full throttle most of the time???????????


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## NSMaple1 (Apr 10, 2016)

Actually, come to think of it, my generator doesn't always run at full throttle either. It's an inverter genny - if it has a light load, it throttles itself back. A great fuel saving feature.


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## Whitespider (Apr 10, 2016)

c5rulz said:


> *So, isn't your splitter then running at less than full throttle most of the time???????????*


No... it runs at full throttle _most_ of the time.
It has a hands-free auto-cycle... a nine second cycle time.
You place a round on it, throw the lever forward, and turn to grab the next round... the round has been split and the ram is on the return stroke by the time you have the next round ready. It's just a matter of dropping it on the beam and throwing the lever again... often before it even finishes the return stroke (which would be before the engine idles down). Even if it don't go that smooth it's still a 9:1 or 9:2 ratio... 9 seconds at full throttle while the ram is moving, and 1 or 2 at idle while the next round is positioned.
*


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## Whitespider (Apr 10, 2016)

Actually... I misspoke... sorry...
The length of the ram stoke is adjustable... so if you're splitting 16 inch long firewood you set the stroke length to 17 inches or so.
Meaning... the cycle time is shortened to about 5 or 6 seconds... so it would be a 6:1 or 6:2 ratio.
*


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## alleyyooper (Apr 11, 2016)

Boy glad I wear boots so I don't get all the chit spread here on my legs.
Any one hear of a machine called a snowmobile? Early ones were fan cooled and you could not run them wide open throttle on trails because it just was not safe. A little later they came out with free air machines those also were not always ran wide open even if you were racing ovals you had to slow for the corners.

There is two free air Polaris TX machines in this picture, one liquid cooled Polaris TXL and a Fan cooled Mercury, all were/are 2 strokes too. My Mercury ran heat gauges, Never varied from a 30 below day to a 30 above day, trail riding or racing it.









Oh I can hear it now ya that is in the snowy cold. So how do you explain the 2 stroke free air motor cycles ran part throttle on roads and trails? You don't even run your car or truck WFO on the roads.
I run my engines to meet the job/load required to get the job done.

 Al


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## Whitespider (Apr 11, 2016)

alleyyooper said:


> *Oh I can hear it now ya that is in the snowy cold. So how do you explain the 2 stroke free air motor cycles ran part throttle on roads and trails? You don't even run your car or truck WFO on the roads.*


Apples and oranges cannot be compared...
We ain't talkin' about 2-cycle snowmobile engines...
We ain't talkin' about large, multi-cylinder, pressure-lubed, liquid-cooled automotive engines...
We're talkin' about small (typically single cylinder and less than 15 HP), splash-lubed, air-cooled, 4-cycle engines.
*


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## Sawyer Rob (Apr 11, 2016)

Whitespider said:


> We're talkin' about small (typically single cylinder and less than 15 HP), splash-lubed, air-cooled, 4-cycle engines.


 Then we are talking about the thousands and thousands of 4 cycle "inverter" gen set motors, mine is splash lubed and I can't remember the last time it revved to WOT!

Mostly it just sits there running for hours on end just above an idle to half throttle...

Hasn't hurt it one bit and it uses a lot less gas with lighter loads on it.

It's been doing this every time I use it, for all the years I've owned it...

SR


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## ckr74 (Apr 11, 2016)

alleyyooper said:


> I run my engines to meet the job/load required to get the job done.


 Exactly. I've been around small engines for a long and even had my own repair service. Small engines will run a long time if taken care of. I do agree that 2 strokes need to be run wide open under any type of load.


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## c5rulz (Apr 11, 2016)

Whitespider said:


> Apples and oranges cannot be compared...
> We ain't talkin' about 2-cycle snowmobile engines...
> We ain't talkin' about large, multi-cylinder, pressure-lubed, liquid-cooled automotive engines...
> We're talkin' about small (typically single cylinder and less than 15 HP), splash-lubed, air-cooled, 4-cycle engines.
> *




Granted apples to oranges.

But the fan cooled snowmobile engine should be much more sensitive to engine RPM in regards to cooling.

FWIW, I took a lazer temp indicator and got around 160 degrees on the crankcase of my splitter after an extended run at 3/4 throttle.


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## GVS (Apr 11, 2016)

Whitespider said:


> *Ha‼*
> My log splitter has an auto-throttle control; it goes to full throttle whenever the ram is moving (when the engine is on-load), and automatically goes to idle when the ram is not moving (when the engine is off-load).
> 
> 
> ...


The only reason the builders went to small engines without operator controlled throttle is (1) less cost to the builder and (2) get the engines to wear out sooner thus selling more engines.I just love starting my snowblower on a sub zero day and having it go right to max goverend RPM and staying there until it's shut off .Not good!My emergency generator goes right up against the govener also to maintain 60 cycle but at least on that engine I can hold the linkage back to keep RPM down until it warms up a bit and it's thrown some oil around in the engine.All the rest of my small engines are run at half to 3/4 maybe 7/8 ,seldom at full.Of course the saws are pined if the chain is in wood.I've never had one blowup or overheat 55+ years .Efficiency is probably higher at full throttle but so is wear since wear is directly related to piston travel.In other words in 1 min.time the piston travels further at 3600 RPM then it does at 3000 RPM.It's been written that all 2 strokes should be run at W/O throttle .Not so .I sure won't run my snowmobile W/O for very long!


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## ckr74 (Apr 11, 2016)

GVS said:


> .Efficiency is probably higher at full throttle but so is wear since wear is directly related to piston travel.


 A piston is only going to go up and down so many times.


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## svk (Apr 11, 2016)

This is starting to get interesting.


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## NSMaple1 (Apr 11, 2016)

Huh, forgot about the snowblower.

Wide open with the chute buried in fresh snow, but part throttle when walking it back to home base or cleaning up some spillage. Or placing the snow just where you want it in a tight space not far away.


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## brenndatomu (Apr 11, 2016)

alleyyooper said:


> Boy glad I wear boots so I don't get all the chit spread here on my legs.





svk said:


> This is starting to get interesting.


I've had mah boots on since page 1...


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## svk (Apr 11, 2016)

brenndatomu said:


> I've had mah boots on since page 1...


There are so many side discussions now I don't even remember what the OP was LOL.


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## NSMaple1 (Apr 11, 2016)

You mean everybody doesn't have their boots on all the time around this place?


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## svk (Apr 11, 2016)

You can tell it's spring break up season with the amount of cabin fever in this place over the last few weeks!


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## GVS (Apr 11, 2016)

ckr74 said:


> A piston is only going to go up and down so many times.


Piston moves up and down more times in one minute at 3600 RPM than it does at 3000 RPM therefore it travels farther in one minute.Double the stroke and multiply by RPM and you have the distance the piston traveled.Multiply that number by the hours in use at 3000 or 3600 RPM continuous and you will see a significant difference in piston travel.


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## ckr74 (Apr 11, 2016)

GVS said:


> Piston moves up and down more times in one minute at 3600 RPM than it does at 3000 RPM therefore it travels farther in one minute.Double the stroke and multiply by RPM and you have the distance the piston traveled.Multiply that number by the hours in use at 3000 or 3600 RPM continuous and you will see a significant difference in piston travel.


Exactly my point. Less RPM=Less wear.


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## Dalmatian90 (Apr 11, 2016)

Skipping pages 2, 3, 4 after comments on the first reminded me of this:

RTFM

Was recently reading a lot on riding mowers, and more than one thread mentioned "Kohler engines habit of backfiring when you shutdown"

I'm rolling my eyes because if you read the Kohler manual, if you have a fuel shutoff solenoid, you leave them at full throttle when you shut them off or, as the manual warns you, they backfire.

Had a semi-portable pump at the firehouse that we were taught by one of the old timers "Always let engines like this idle down for a few minutes before shutting if off." Off course it would backfire, and eat about three belts a year. Until I Read The Fracking Manual which first the Kohler manual warned you full idle or it backfires, and the Pump manufacturer's manual that warned if it backfires often it'll eat belts. 

Change to what the manual said, no more belts being eaten.

So either find the manual for the model engine you have, or at least narrow down the question to a specific make and model of engine because I really doubt every single one cylinder gasoline engine was designed to either be run WOT all the time, or variable throttle all the time.


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## Whitespider (Apr 11, 2016)

GVS said:


> *Efficiency is probably higher at full throttle but so is wear since wear is directly related to piston travel.In other words in 1 min.time the piston travels further at 3600 RPM then it does at 3000 RPM.*





ckr74 said:


> *Less RPM=Less wear.*


You guys can't actually believe it's that simple?? That would only be true _if all else remains equal_.

If you have a piece of equipment that requires an 8 HP engine, which engine will wear out first... a 10 HP engine running at half throttle (translates to about 7 HP output)... or, a 8 HP engine running full throttle?? I'll give you the answer... the 10 HP running at half throttle will take a crap well before 8 HP running full throttle.

Wear is much more effected by load (or the ratio of load to output power), heat, lubrication, and the amount of fuel being delivered to the engine.
I guarantee if you take two identical small 4-cycle engines, run one at 3000 RPMs, the other at 3600 RPMs, and apply the same identical load to both of them... the engine running at 3600 RPMs will outlast the engine running 3000 RPMs. That's because the ratio of load to output power causes the slower running engine to work harder to maintain RPMs (the governor is opening the throttle more often and for longer periods), and the slower RPMs are delivering less cooling air and lubrication.

And if you ran them both with _zero_ load on them... someone would likely be digging your grave before either of them wore out 
Heck... I replaced the head gasket on my 35-year-old splitter engine a couple years back and you could still see the crosshatch marks on the cylinder wall.
*


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## Whitespider (Apr 11, 2016)

Dalmatian90 said:


> *I really doubt every single one cylinder gasoline engine was designed to either be run WOT all the time, or variable throttle all the time.*


4-cycle engines do not run at "WOT"... the governor opens and closes the throttle as needed to maintain RPMs.
The only time the throttle goes "wide open" is when RPMs drop below the governor set point, and only stays there long enough to recover the RPMs... and it don't matter if the throttle (governor control) is set for half throttle or full throttle, the actual throttle still goes "wide open" to recover RPMs.



Dalmatian90 said:


> *I'm rolling my eyes because if you read the Kohler manual, if you have a fuel shutoff solenoid, you leave them at full throttle when you shut them off or, as the manual warns you, they backfire.*


The manual for the Kohler engine on my grass cutter says to run the engine at _off-load_ _full_ _throttle_ for a couple of minutes to _cool_ the engine _before_ shutting it down.
*


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## Whitespider (Apr 11, 2016)

Hey... how 'bout we get back to the OP??



blkcloud said:


> *I hate hi jacking threads.. but.. talking about running air cooled engines at half throttle.. I have always been told by small engine mechanics that, the faster one runs, the cooler it is.. on guy was replacing a garden tiller engine a elderly lady had because it overheated.. he said she would never run it full throttle and it burned its self up..*


Yes... what you've *"always been told by small engine mechanics"* is true... always run your small 4-cycle engines at full throttle when on-load.
*


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## Sawyer Rob (Apr 11, 2016)

Whitespider said:


> 4-cycle engines do not run at "WOT"... the governor opens and closes the throttle as needed to maintain RPMs.


 AND your answer to post #70 is?????

AND you can replace WOT with, wide open "governed" MAX rpm...

SR


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## ChoppyChoppy (Apr 11, 2016)

I have a Kawaski on my ZTR that backfires no rhyme or reason. Loud enough to have people walk outside to see what guns are getting shot (to compare to what they own of course).

I shut it off with an idle down. It's SOP for every engine I've run aside from gen sets.


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## CR888 (Apr 11, 2016)

How would things change if the govenor system was to be removed? My honda push mower has a govenor, and I run it at various throttle settings according to how much load the grass is creating. I do use full throttle when grass is thick and high but that is not always normal conditions. Model is HRU196.


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## Del_ (Apr 11, 2016)

CR888 said:


> How would things change if the govenor system was to be removed? My honda push mower has a govenor, and I run it at various throttle settings according to how much load the grass is creating. I do use full throttle when grass is thick and high but that is not always normal conditions. Model is HRU196.



It would over rev and explode.


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## Whitespider (Apr 11, 2016)

Sawyer Rob said:


> *AND your answer to post #70 is?????
> AND you can replace WOT with, wide open "governed" MAX rpm...*


This post??



Sawyer Rob said:


> *Then we are talking about the thousands and thousands of 4 cycle "inverter" gen set motors, mine is splash lubed and I can't remember the last time it revved to WOT!
> Mostly it just sits there running for hours on end just above an idle to half throttle...
> Hasn't hurt it one bit and it uses a lot less gas with lighter loads on it.*


First of all... no... you cannot replace WOT with wide open "governed" MAX rpm.
WOT means "wide open throttle"... maximum governed RPM (full throttle) can be just slightly off idle position if there's no load on the engine, or something more than that if the engine is on-load. The truth is... the _throttle_ _position_ is continuously being _varied_ by the governor slightly... small 4-cycle engines are controlled by _variable_ _throttle_ _position_.

Now... about those inverter gen sets... and I didn't address it before because it gets highly technical, but I'll keep it basic.
First question for ya'... have you put a tachometer on your generator engine when you believe it's running at ½ throttle or less??

Inverter gen sets use a high efficiency alternator (rather than a generator) to produce a high frequency alternating current (much higher than 60HZ), which is then run through a diode bridge to convert it into D/C, which is then run through the inverter to convert it back into low frequency A/C (normally, very clean, 60HZ A/C). Those high efficiency alternators use magnets, rather than brushes... meaning very little resistance (very little load on the engine). The "load" (what you're powering) is placed on the inverter... only if the inverter needs more input to keep up with demand is load placed on the alternator. For all practical purpose, the engine is running _off-load_ unless you place a very high demand on the inverter. The difference is _off-load_ or _on-load_... there ain't a problem running less than full throttle when _off-load_... as I've said.

Not all inverter gen sets adjust the engine RPMs down during low load... many run at a steady RPM (whatever the specs call for, it ain't necessary for it to be 3600 RPMs because the alternator is high frequency, it ain't a 60HZ generator). However, those that use electronic modules (i.e. small computers) to control current and conversions will often also adjust the engine RPMs for low/no load conditions. Typically these RPM adjusting will be more expensive and often also use "special purpose" commercial engines designed to run in an operating range of 2000-3600 RPMs... or 2500-3600 RPMs... or even 2800-3060 RPMs (3060 is not a typo... 2800-3060 is a common "special purpose"). This is why you normally cannot go get parts for small engines using just the model number... you also need the spec number, or serial number, or whatever depending on manufacturer. The model number basically is the block/frame... it's the other numbers that determine what the engine is, and what its specs are.

As I posted earlier...
Dad's old pressure washer has a "special purpose" 3.5 HP Briggs on it... designed to run and produce peak power at 3000 RPMs per specifications.
The reason is the water pump bolted to it is rated for a maximum RPM of 3000.
*


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## Whitespider (Apr 11, 2016)

Del_ said:


> *It would over rev and explode.*


And it would happen right quick 
*


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## Sawyer Rob (Apr 11, 2016)

I know how they work... and yes on the tach...

Point being, it doesn't need to be run fast to run cool OR last a long time (or use less fuel) WHICH is counter to what you've been preaching here! lol 

SR


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## Marshy (Apr 11, 2016)

Dalmatian90 said:


> *Skipping pages 2, 3, 4* after comments on the first reminded me of this:
> 
> RTFM
> ...


Glad Im not the only one.


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## Whitespider (Apr 12, 2016)

Sawyer Rob said:


> *Point being, it doesn't need to be run fast to run cool OR last a long time (or use less fuel) WHICH is counter to what you've been preaching here! lol*


What is it you don't understand about off-load and on-load??
Your engine throttles back because it's off-load... which is exactly what I've be "preaching".
Do you see the governor opening the throttle to maintain the throttled back RPM?? No, you don't‼ Because the damn thing is off-load‼
*


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## NSMaple1 (Apr 12, 2016)

Loads aren't on or off like a light switch - they are variable. My genny throttles back with less load, throttles up with more. It doesn't wait until there is no load to throttle back.


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## GVS (Apr 12, 2016)

Whitespider said:


> This post??
> 
> 
> First of all... no... you cannot replace WOT with wide open "governed" MAX rpm.
> ...


If it's making HZ it's an alternator.Doesen't make any difference weather 50,60 or 400 HZ.


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## Whitespider (Apr 12, 2016)

NSMaple1 said:


> *Loads aren't on or off like a light switch - they are variable. My genny throttles back with less load, throttles up with more. It doesn't wait until there is no load to throttle back.*


Unless it's an inverter generator, it's running at approximately 3600 RPMs all the time.

The governor opens and closes the throttle plate to maintain RPMs according to load... it may be "throttling back" under lighter load, but it's still running at maximum RPMs. The higher the load, the more fuel required to carry it... if there's no load the throttle barely opens past idle to maintain 3600 RPMs. That's why I asked @Sawyer Rob if he'd put a tachometer on his engine when he believes it's running at ½ throttle or less... a throttle plate half open on an off-load engine will cause the engine to over rev. Throttle plate position is relative to engine load, not so much engine RPM.

Not an exact comparison... but if you're driving your truck down hill (off-load) at 60 MPH you barely press on the throttle peddle compared to driving up hill (on-load) at 60 MPH. If the hill is steep enough you need no throttle to maintain 60 MPH on the way down (might even need brakes), and going up hill may require you to floor it (and you may still lose speed). On a small engine the governor takes care of the throttle position for you... kind'a like setting the cruise control.
*


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## Whitespider (Apr 12, 2016)

GVS said:


> *If it's making HZ it's an alternator.Doesen't make any difference weather 50,60 or 400 HZ.*


That's false.

An alternator produces electricity by spinning a magnetic field inside a stator winding.
A generator produces electricity by spinning an armature winding inside a magnetic field.

Alternators produce electricity on demand (they can put the driving engine _off-load_).
Generators produce electricity continuously (the driving engine is always _on-load_).

Generators need to be polarized... alternators do not.

Alternators are capable of higher output than generators.

And there's more...
*


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## ckr74 (Apr 12, 2016)

Whitespider said:


> Throttle plate position is relative to engine load, not so much engine RPM.


The throttle plate is directly related to engine RPM. The purpose of the governor is to keep a constant RPM under a said load.


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## GVS (Apr 12, 2016)

Whitespider said:


> That's false.
> 
> An alternator produces electricity by spinning a magnetic field inside a stator winding.
> A generator produces electricity by spinning an armature winding inside a magnetic field.
> ...


An alternator produces AC currant.Generator -DC currant.If DC is needed and an Alt.is in use,send the AC through rectifier and DC comes out.If AC is needed and a generator is in use,send it through an inverter and AC comes out.Pretty simple really.


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## NSMaple1 (Apr 12, 2016)

Whitespider said:


> Unless it's an inverter generator, it's running at approximately 3600 RPMs all the time.
> 
> The governor opens and closes the throttle plate to maintain RPMs according to load... it may be "throttling back" under lighter load, but it's still running at maximum RPMs. The higher the load, the more fuel required to carry it... if there's no load the throttle barely opens past idle to maintain 3600 RPMs. That's why I asked @Sawyer Rob if he'd put a tachometer on his engine when he believes it's running at ½ throttle or less... a throttle plate half open on an off-load engine will cause the engine to over rev. Throttle plate position is relative to engine load, not so much engine RPM.
> 
> ...



Mine is an inverter. It does not run max RPMs all the time. Introduce a small load, it runs half speed. Increase load, it ramps up to max speed. Take some load off, it throttles back to half speed again. Has a switch on it, for Eco Mode. Switch that off & it runs max speed all the time. Switch it on, it reduces speed with reduction in load.

And on the un-exact truck comparison - your truck speed might maintain with the barely pressed throttle going down a hill, but the engine speed doesn't. It drops. My auto doesn't anyway.


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## sledge&wedge (Apr 12, 2016)

Yesterday I ran my Fiskars at WOT for a few hours but then the governor came out and told me it was time to throttle back and help her off-load the groceries from the car. Then I splashed a few 12oz. cans of high-efficiency coolant around and let off a few emissions. Then I throttled back up to WFO so I could get my damn wood split and stop arguing about 4-stroke engines and enjoy my afternoon.


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## Whitespider (Apr 12, 2016)

GVS said:


> *An alternator produces AC currant.Generator -DC currant.If DC is needed and an Alt.is in use,send the AC through rectifier and DC comes out.If AC is needed and a generator is in use,send it through an inverter and AC comes out.Pretty simple really.*


I have no idea where you get such a silly notion... both alternators and generators produce alternating current... unless you add some form of rectification.
An alternator is not called an alternator because it produces alternating current... an alternator is called an alternator because it alternates its on/off status according to demand... something a generator cannot do.
A generator was originally called a dynamo... but its full technical name is "_Alternating_ _Current_ Generator".
An "alternator" is also an "Alternating Current _Generator_" that is _also_ capable of automatically "alternating" its on/off status according to demand.

There are what's called D/C generators, but really, they're just A/C generators with rectifiers (just as automotive alternators use rectifiers to become D/C alternators)... remove the rectifiers and a D/C generator becomes an A/C generator (just as automotive alternators would become A/C alternators).
Before the common availability of rectifier diodes, multiple windings and commutator slip rings were used for rectification when D/C was preferable.
(Commutator slip rings can't work with an alternator because the winding is in the stator, not the armature.)

Both generators and alternators produce alternating current... and both can be rectified into direct current.
Both have advantages and disadvantages... depending on purpose. Alternators are capable of producing (on demand) higher output than generators... but generators can handle heavier sustained loads than alternators without burning out.
C'mon man, think about it, what does your local power company call those big-azz things that "generate" the alternating current supplied to your home??
C'mon man, they call them generators, not alternators... that's because they ain't alternators, they're generators... an alternator would overload and burn out if used for that purpose. That's why inverter gen sets use inverters fed by rectified current from an alternator... because if you placed the load directly on the alternator it would overload and burn out. Just as a completely dead battery in your car can burn out an alternator... but it won't harm a generator.
*


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## Whitespider (Apr 13, 2016)

NSMaple1 said:


> *And on the un-exact truck comparison - your truck speed might maintain with the barely pressed throttle going down a hill, but the engine speed doesn't. It drops. My auto doesn't anyway.*


Your auto obviously has an automatic (indirect drive) transmission, not a standard (direct drive) transmission.
Sort'a like an inverter generator places the load _indirectly_ on the engine, and a standard generator places the load _directly_ on the engine.



NSMaple1 said:


> *Has a switch on it, for Eco Mode. Switch that off & it runs max speed all the time. Switch it on, it reduces speed with reduction in load.*


Eco-Throttle (economy) Switch is a Honda Generator feature (some others have similar)... have you read the manual on the use of it??
It is only intended to be used when there is a light load, or no load on the generator... basically, when the engine is _off-load_‼ If the generator is connected to heavy and/or changing loads the Eco system is to be turned off.

_Eco-Throttle™ Switch
The Eco-Throttle system automatically reduces engine speed when all loads are turned off or disconnected. When appliances are turned on or reconnected, the engine returns to the proper speed to power the electrical load.

*If high electrical loads are connected simultaneously, turn the Eco-Throttle switch to the OFF position to reduce voltage changes.*

ON – Recommended to minimize fuel consumption and further reduce noise levels *when a reduced load or no load* is applied to the generator.
OFF – The Eco-Throttle system does not operate. Generator operates at full speed.

With the switch in the ON position, engine speed is automatically lowered when loads are *reduced, turned off, or disconnected*. When appliances are turned on or reconnected, the engine returns to the proper speed to power the electrical load. In the OFF position, the Eco-Throttle system does not operate.

Appliances with large start-up power demands *may not allow the engine to reach normal operating rpm* when they are connected to the generator. *Turn the Eco-Throttle switch to the OFF position* and connect the appliance to the generator. If the engine still will not reach normal operating speed, check that the appliance does not exceed the rated load capacity of the generator.

If high electrical loads are connected simultaneously, turn the Eco-Throttle switch to the OFF position to reduce voltage changes.

The Eco-Throttle system is not effective for use with appliances or tools that require only momentary power. If the tool or appliance will be turned ON and OFF quickly, the Eco-Throttle switch should be in the OFF position._
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## NSMaple1 (Apr 13, 2016)

That reads about the same as what I said. I just didn't use as many words.

Here's the wording pasted right from my manual:

'ECONOMICAL MODE SWITCH-(G) FIG.8. When placed in the “On” position, the engine speed will be kept at idle automatically when an electrical load is disconnected and returns to proper speed to power the electrical load when reconnected. This is recommended to minimize fuel consumption during operation. Before using the electrical appliance, switch the Economical Mode switch to the “Off” position.'

Proper speed for the load. A light load isn't no load - it's still some load.

Bottom line is, the motor that is in it doesn't need to run max RPM at all times or even at those times when there is just SOME load on it. Otherwise that switch wouldn't be there. Or all of the other small engines I have wouldn't have throttle (RPM) controls.

Boots? Almost time to dig the hip waders out....


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## GVS (Apr 13, 2016)

Whitespider said:


> I have no idea where you get such a silly notion... both alternators and generators produce alternating current... unless you add some form of rectification.
> An alternator is not called an alternator because it produces alternating current... an alternator is called an alternator because it alternates its on/off status according to demand... something a generator cannot do.
> A generator was originally called a dynamo... but its full technical name is "_Alternating_ _Current_ Generator".
> An "alternator" is also an "Alternating Current _Generator_" that is _also_ capable of automatically "alternating" its on/off status according to demand.
> ...





Whitespider said:


> I have no idea where you get such a silly notion... both alternators and generators produce alternating current... unless you add some form of rectification.
> An alternator is not called an alternator because it produces alternating current... an alternator is called an alternator because it alternates its on/off status according to demand... something a generator cannot do.
> A generator was originally called a dynamo... but its full technical name is "_Alternating_ _Current_ Generator".
> An "alternator" is also an "Alternating Current _Generator_" that is _also_ capable of automatically "alternating" its on/off status according to demand.
> ...


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## GVS (Apr 13, 2016)

An alternator is called that because the AC CURRANT it produces alternates direction depending on it's speed of rotation or the number of windings in it's stator. A DC GENERATOR's currant may be interrupted but it isn't alternated as if it was an alternator.


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## Oldman47 (Apr 14, 2016)

Whitespider said:


> I have no idea where you get such a silly notion... both alternators and generators produce alternating current... unless you add some form of rectification.
> An alternator is not called an alternator because it produces alternating current... an alternator is called an alternator because it alternates its on/off status according to demand... something a generator cannot do.
> A generator was originally called a dynamo... but its full technical name is "_Alternating_ _Current_ Generator".
> An "alternator" is also an "Alternating Current _Generator_" that is _also_ capable of automatically "alternating" its on/off status according to demand.
> ...


Well, sometimes you know what you are talking about but on automotive applications the thing that is called a generator uses a commutator to directly produce a rippled DC output to the wires it is connected to. A thing they call an alternator produces an AC output that is run through a rectifier circuit to get that same rippled DC output from the rectifier, not from the generating device. An alternator produces more power because its output winding is the stator, a large winding that is easily cooled. A generator, in automotive terms, produces its output in the rotor and thus cannot produce near as much power without overheating.
Power output of either a "generator" or an "alternator" is controlled by a regulator that typically controls the field winding voltage although other approaches are used for some smaller alternator circuits like the bleed device used as a regulator on some motorcycles. In that case the generated current is bled off to ground as needed to control voltage and the alternator is run wide open.
Having worked in the power industry I am well aware that generator, meaning a direct DC producing device is unique to the automotive industry. Everyone else calls any generating device a generator. The only place I have run into the word alternator is in the auto industry.
As far as the old time "dynamos", both AC and DC generators were called dynamos in the infancy of the power business and both AC and DC power were each sold by utilities at that time. GE and Westinghouse, the companies producing dynamos each had their own preference opposite to each other but when high voltage transmission became a need for long distances the AC form won out because it is easy to step up and down in voltage.


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## sb47 (Apr 14, 2016)

blkcloud said:


> I hate hi jacking threads.. but.. talking about running air cooled engines at half throttle.. I have always been told by small engine mechanics that, the faster one runs, the cooler it is.. on guy was replacing a garden tiller engine a elderly lady had because it overheated.. he said she would never run it full throttle and it burned its self up..



I think it all depends on the engine design and how it's designed to operate.
Small 2 stroke motors tend to run better wide open.
While small 4 stroke motors run better at a slower speed.
If your running hydraulic's the hydraulic's need a slower RPM.
Diesel motors tend to run better at a slower RPM, except for a cat motor that is designed to run at a high RPM.
The reason they run cooler at higher RPM is because the fly wheel usually has fan blades that push more air at higher RPM's
Most small motors tend to not oil well or the wrong oil is used or never changed.
It all depends on the motor and it intended use.


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## sb47 (Apr 14, 2016)

And to add, most problems may have more to do with air/fuel mixture. Running rich or lean will make a huge difference in engine temps.


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## Whitespider (Apr 15, 2016)

Oldman47 said:


> *The only place I have run into the word alternator is in the auto industry.*


Well... now you know of a second place the term is used... alternators are used on inverter gen sets.

@Oldman47 ,
How is anything you posted different than what I have??
Here's a recap...

"An alternator produces electricity by spinning a magnetic field inside a stator winding.
A generator produces electricity by spinning an armature winding inside a magnetic field.
Alternators are capable of higher output than generators.
...both alternators and generators produce alternating current... unless you add some form of rectification.
Before the common availability of rectifier diodes, multiple windings and commutator slip rings (on generators) were used for rectification when D/C was preferable.
(Commutator slip rings can't work with an alternator because the winding is in the stator, not the armature.)
Both generators and alternators produce alternating current... and both can be rectified into direct current.
Both have advantages and disadvantages..."
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## Whitespider (Apr 16, 2016)

GVS,
Note below these are A/C and D/C generators, not alternators... there is no stator, the electricity comes from the armature in a generator, it comes from the stator in an alternator.
Both A/C and D/C generators produce an alternating current in the armature... but the split ring commutator of the D/C _generator_ rectifies it into a D/C output by polarizing the brushes... the current can only flow one way. This accomplishes the same thing as a rectifier bridge in an alternator... it blocks the reverse flow. It "converts" A/C current into D/C current... which is the definition of electrical rectification. It simply ain't possible to "generate" D/C current by a rotation within a magnetic field... the north/south poles can only "generate" A/C which must be rectified into D/C current in some way.

A standard (non-inverter) gen set utilizes an A/C _generator_... not an alternator... the difference is in the commutator.














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