# 2 Stihl 090's 50" bar White Ash



## Timberframed (Jan 19, 2011)

[video=youtube;JDZ8F4PS64s]http://www.youtube.com/watch?v=JDZ8F4PS64s[/video]


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## gemniii (Jan 19, 2011)

YOU SORRY ......

Is that you?

MORE DETAILS!!!!

Any source for inexpensive dual ended bars?

Stick that on your BSM!!

Bar length envy


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## Timberframed (Jan 19, 2011)

Run of the mill Granberg frame. Around an 1¼" per second if my memory serves me correct. 4½ years ago. Not my rig but it was my Ash if I didn't do something soon. FIL's property.


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## pwoller (Jan 19, 2011)

Dang need oxygen to run those saws.


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## BobL (Jan 19, 2011)

Was it a dry log? There seems to be a awful lot of dust
The guy on the RHS also seems to be standing in a blue fog - maybe they are running 25:1?


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## Brmorgan (Jan 19, 2011)

Two 090s singing harmony is a beautiful thing.  Nice setup!


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## losttheplot (Jan 20, 2011)

Timberframed said:


> . Around an 1¼" per second if my memory serves me correct.




If your talking about the speed of the cut;

The video clip was 100 seconds, times an inch and a quarter per second, would be 125 inches or 10 feet and 5 inches.

That"s bloody impressive.:good:


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## dave k (Jan 20, 2011)

Very nice, a pal of mine has a 50" set up using two 076's which he uses to reduce big logs ready for putting on his Stenner.
I wonder if the saws had slightly different settings which would mean the one on the right as Bobl points out was a bit smokey bearing in mind the way the 090's choke themselves to prevent over speed ? Anyway it was great to hear them !


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## Timberframed (Jan 20, 2011)

losttheplot said:


> If your talking about the speed of the cut;
> 
> The video clip was 100 seconds, times an inch and a quarter per second, would be 125 inches or 10 feet and 5 inches.
> 
> That"s bloody impressive.:good:


 
My memory does not serve me corectly


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## IndyIan (Jan 22, 2011)

What chain were you running to bog two 090's? I guess with two guys its easy to lean into the saws alot.


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## Rusty-880 (Jan 29, 2011)

BobL said:


> Was it a dry log? There seems to be a awful lot of dust
> The guy on the RHS also seems to be standing in a blue fog - maybe they are running 25:1?


 
I've read a few people saying things like this. But 25:1 WILL NOT foul a chainsaw. I run 16:1 in my 880 milling. Does not blow smoke and does not leave muffler oily. If a saw is smokey its air/fuel ratio not oil/fuel ratio.

I'd love to run 2 090's or 880's on a mill!


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## BobL (Jan 30, 2011)

Welcome Rusty - good to have another Aussie on this forum.



Rusty-880 said:


> I've read a few people saying things like this. But 25:1 WILL NOT foul a chainsaw. I run 16:1 in my 880 milling. Does not blow smoke and does not leave muffler oily. If a saw is smokey its air/fuel ratio not oil/fuel ratio.


 
Yep - on thinking about it again I agree. If the saw is tuned to suit modern 2S lubes will hide a lot of visible smoke particles even down to 16:1.

I'm interested in your rationale for running 16:1.

I also notice on another thread that you have made a pretty significant muffler mod.
Did you have to re-jet the carby to take into account the increased air/fuel ration these two factors would cause ?


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## mtngun (Jan 30, 2011)

I was skeptical of the need to post milling videos, but after watching this one, it does have some value -- you can observe the cutting speed, and it's pretty darned slow. 

I've never milled monster wood, but I have to wonder why BobL and BillStewe can mill monster slabs with a single 880, yet in the old days it was common to use dual powerheads, as in this video. Seems like you'd need a more aggressive chain to take advantage of dual 090's ?


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## Rusty-880 (Jan 31, 2011)

BobL said:


> Welcome Rusty - good to have another Aussie on this forum.
> 
> 
> 
> ...


 
I was originaly running 25:1 and .404'' skip chain. When milling ironbarks in summer (not huge but had been sitting a few years), the saw was getting that hot it would boil the fuel in the tank. It wasn't running lean, if anything a tad rich. I ended up getting a 44" GB bar made with 3/8" tip. This alone would most likely have sufficed (now cuts in nearly half the time with half the fuel) but needed to do something in the mean time.
Didn't need to rejet carb, still enough adjustment (with limiter tabs removed) to run quite rich (enough to have the fuel fumes from exhaust sting your eyes!)


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## BobL (Jan 31, 2011)

Rusty-880 said:


> I was originaly running 25:1 and .404'' skip chain. When milling ironbarks in summer (not huge but had been sitting a few years), the saw was getting that hot it would boil the fuel in the tank. It wasn't running lean, if anything a tad rich. I ended up getting a 44" GB bar made with 3/8" tip. This alone would most likely have sufficed (now cuts in nearly half the time with half the fuel) but needed to do something in the mean time.
> Didn't need to rejet carb, still enough adjustment (with limiter tabs removed) to run quite rich (enough to have the fuel fumes from exhaust sting your eyes!)


 
I am surprised you had trouble with fuel boiling at 25:1. I avoid milling in summer but have milled several big logs with my 60" bar when it has been over 100F and have never had mix boiling and I use 40:1. I would use 50:1 but I need 40:1 for my 076 and don't like to have different mixes laying around going stale.
 
A quick calculation shows that the boiling point of mix will only change by between 3 and 5ºC by going from 25:1 to 16:1 while the range experienced by a working saw will be ~30 times greater than that this.

If your saw is getting hot enough to boil the mix that suggests another problem. I have a temperature gauge on my saw and the typical things that kick the temperature up above normal are 
- pushing too hard 
- no auxiliary oiler
- blunt chain 

The thing I don't like about using too much lube is the stuff they use in it is not good for the operator. I usually get a headache after about a hour of using saws at 25:1.


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## mtngun (Jan 31, 2011)

All my saws will boil the fuel like crazy in the summer. 

Even a gas jug sitting in the sun will boil. When you open the cap, gas bubbles and shoots out. 

My altitude doesn't help, nor does the ethanol.


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## masculator (Feb 1, 2011)

mtngun said:


> All my saws will boil the fuel like crazy in the summer.
> 
> Even a gas jug sitting in the sun will boil. When you open the cap, gas bubbles and shoots out.
> 
> My altitude doesn't help, nor does the ethanol.



Ethanol is for chumps!!!! no chainsaw should run it. Run rich, and oily, use high octane fuel and synthetic lube, plugs are cheaper than jugs!!!!


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## masculator (Feb 1, 2011)

BobL said:


> Welcome Rusty - good to have another Aussie on this forum.
> 
> 
> 
> ...



Correct me if I am wrong but wouldn't 16 to 1 allow you to run leaner and still provide sufficient lube for the saw, hence increasing cutting time per tank and possibly a little more power while you are cutting?

As I say I may be wrong and like you BobL I run 40 to 1 for similar reasons to you.


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## BobL (Feb 1, 2011)

mtngun said:


> All my saws will boil the fuel like crazy in the summer.
> 
> Even a gas jug sitting in the sun will boil. When you open the cap, gas bubbles and shoots out.
> 
> My altitude doesn't help, nor does the ethanol.


 
I too sometimes see bubbling and shooting of fuel from a just opened warm/hot container but leave it for a few seconds and it stops bubbling. It's just excess vapor above the surface and inside the fuel equilibrating with the atmosphere, something like the effect of opening a warm soda. It's a sort of a temporary mini-boil but it does not mean the fuel inside the container is boiling. I know a lot of think it's boiling inside the container, but to be boiling it would have to continue to bubble long after the cap has been removed.

|


masculator said:


> Correct me if I am wrong but wouldn't 16 to 1 allow you to run leaner and still provide sufficient lube for the saw, hence increasing cutting time per tank and possibly a little more power while you are cutting?.



But with milling you don't want it running leaner, if anything it needs to run richer. Running any milling saw on the lean side is asking for problems.


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## olyman (Feb 1, 2011)

BobL said:


> I too sometimes see bubbling and shooting of fuel from a just opened warm/hot container but leave it for a few seconds and it stops bubbling. It's just excess vapor above the surface and inside the fuel equilibrating with the atmosphere, something like the effect of opening a warm soda. It's a sort of a temporary mini-boil but it does not mean the fuel inside the container is boiling. I know a lot of think it's boiling inside the container, but to be boiling it would have to continue to bubble long after the cap has been removed.
> 
> |
> 
> But with milling you don't want it running leaner, if anything it needs to run richer. Running any milling saw on the lean side is asking for problems.


 
yup,,and me thinks the extra rich oil to gas mix helps out plenty also--


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## Rusty-880 (Feb 2, 2011)

BobL said:


> I know a lot of think it's boiling inside the container, but to be boiling it would have to continue to bubble long after the cap has been removed.
> 
> QUOTE]
> 
> ...


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## BobL (Feb 2, 2011)

Rusty-880 said:


> It was boiling, tank was fairly warm to touch and bubbled away for a good few minutes.





> My main thought on extra oil was to give it a bit more lube so there might be a bit more chance that it would'nt seize.



Unless straight gas is used, it's not the lack of lube that is the prime cause of seizure but the temperature. A two stroke needs very little lube to run even under very hard loads provided it is well cooled and well tuned. A CS will even run on 100:1 but at those ratios there is very little room for error so that's why most manufacturers generally recommend 50:1. It would be interest to know why they tell operators, who wish to use anything other than their brand lube, at 25:1, is beyond me. I can't help thinking it is to provide a financial incentive for operators to use their branded product.

The point I'm trying to get across, especially to newbie millers, is that significantly reducing the mix ratio and not re-tuning (to make up for the fact that reducing the ratio leans the mix) can contribute to seizure. Although it's still a good idea to retune, going from 16:1 to 25:1 changes the mix ratio by 2% which is within atmospheric press change tolerances so the chance of problems are low even if the saw is not retuned. Going from 50:1 to 16:1 is a 4% change, which when added onto anything else that is on the lean side and can cause problems. This can be something a simple as running the CS on it's side too close to the ground so the CS is inadequately cooled - I've seen this happening with people milling on their knees and the log on the ground with the mill and the saw almost touching the ground. Yet another good reason not to mill on the ground.



> When it comes to race cars, chainsaws ect tho you only want to tune for max power. Under that kind of load you will only damage it and probly take longer and use more fuel because you have less power.
> To an extent the more power you have the more fuel efficient it is. (Dosn't work as hard to do same amount of work)



I don't quite understand what you mean? 

In a stock form and tuned for max power most CS used in CS mills run the risk of overheating and seizure because they are not designed to run in mills. Unlike a motor vehicle which generally has more than sufficient cooling capacity at max power, one need equal to or maybe greater than requiring max power when milling with a CS is keeping the saw cool. A simple way to do this to stock saws is to run the saw a little richer since the unburnt fuel helps carry away additional heat. This is why extreme porting (even more "extra max power") is not advisable for a milling CS. Just lowering the mix does nothing for cooling since the extra lube carries away very little heat and is in fact unnecessary for lubrication.

The other way to cool a stock saw is to open up the muffler - it's one of the few mods that, provided retuning takes place, can generate more power and cooler running. Some mild porting can also probably help do the same thing.


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## masculator (Feb 2, 2011)

Correct me if I am wrong but I thought the boiling point for petrol was between 75 and 85 degrees celsius, depending on a number of factors (been a long time since I worked for shell) vaporisation, like when boiling water, will occur at a lower temperature, which will increase the deterioration of the fuel and speed the drop of octane. It also reduces the ratio of volatile elements in relation to oil so if for instance you mixed at exactly 50 to 1 after 15 minutes in the can in the sun you may have lost say 5 percent (completely hypothetical figures) of the volatile hydrocarbons but retained 99.999% of the heavier lubricating oil (which has a much higher evaporation point) you may have reduced your mix ratio to say 45 to 1, and the octane rating of the fuel may have dropped 1 or 2 points (maybe even more.) and this is why I only mix what I will use and put the excess through my mower with a low tech briggs and stratton.


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## masculator (Feb 2, 2011)

BobL said:


> .... It would be interest to know why they tell operators, who wish to use anything other than their brand lube, at 25:1, is beyond me. I can't help thinking it is to provide a financial incentive for operators to use their branded product.



The main reason that they do this BobL is the fact that in some countries such as PNG and The south americas, and african countries they use the same oil to lube their bar as they use to mix their 2 stroke, and this may be anything from rockdrill oil to gear oil or in some cases virtually crude oil. there are also some companies that produce very low quality 2 stroke oils (Lacking the solvents that keep the oil in solution with the fuel, again normally in the lesser developed countries.) Hence it covers their ass as far as warranty goes.


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## masculator (Feb 2, 2011)

olyman said:


> yup,,and me thinks the extra rich oil to gas mix helps out plenty also--



You can suck that oil smoke down olyman, I get a bad enough headache at 40 to 1, and when I have run at 25 to 1 it was eye watering and I could almost feel the oil dripping off me after 2 tanks. NOT for me thanks, I use the good oil and warranty covers it, or I fix it (not that I have to EVER due to fuel issues.)


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## Rusty-880 (Feb 3, 2011)

masculator said:


> You can suck that oil smoke down olyman, I get a bad enough headache at 40 to 1, and when I have run at 25 to 1 it was eye watering and I could almost feel the oil dripping off me after 2 tanks. NOT for me thanks, I use the good oil and warranty covers it, or I fix it (not that I have to EVER due to fuel issues.)


 
You guys must have some serious sensitivities to oils/petrol. I cant change rods in the carb on my chev without gotting crook and running a saw has never made me crook, no matter what mix im running. 
I ment when you are running something like a saw or race car (something under a decent load and working hard) you never try and tune for economy, always best power setting- usually fractionly rich.


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## BobL (Feb 3, 2011)

Rusty-880 said:


> You guys must have some serious sensitivities to oils/petrol. I cant change rods in the carb on my chev without gotting crook and running a saw has never made me crook, no matter what mix im running.



Yep I admit I'm probably more sensitive than most operators, even drying oil based paints make me sick. Some say that chemically sensitive people are similar to how canaries were used re in minesites. When I work on engines in enclosed spaces I need really good ventilation - I usually put my dust extractor on and place a flexi hose inlet on the bench.


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## betterbuilt (Feb 3, 2011)

Most of the furniture I build is for the chemically sensitive. All the finish I use is No VOC. I have to go through a long and painful process of eliminating a bunch of different factors. 

I wouldn't call myself sensitive but, I would say I'm more aware than most.


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## mtngun (Feb 3, 2011)

masculator said:


> Correct me if I am wrong but I thought the boiling point for petrol was between 75 and 85 degrees celsius,


Good question, thankfully we have the internet at our fingertips.

Apparently, there is no easy answer, because of all the added ingredients.

Winter gasoline is different than summer gasoline. Winter blends contain stuff like butane and iso-butane to make it vaporize readily in cold weather.


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## BobL (Feb 3, 2011)

masculator said:


> The main reason that they do this BobL is the fact that in some countries such as PNG and The south americas, and african countries they use the same oil to lube their bar as they use to mix their 2 stroke, and this may be anything from rockdrill oil to gear oil or in some cases virtually crude oil. there are also some companies that produce very low quality 2 stroke oils (Lacking the solvents that keep the oil in solution with the fuel, again normally in the lesser developed countries.) Hence it covers their ass as far as warranty goes.


 
I re-read a recently downloaded 880 owners manual and cannot find any reference to using non stihl lubes at 25:1. 





No mention of 25:1 and all lubes to be used at 50:1


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## Rusty-880 (Feb 3, 2011)

The owners manual that came with my 880 said Stihl oil 50:1 all other brands 25:1. Bought it nearly two years ago. From what I've been told Stihl oil is made by Castrol. 

In the local Stihl shop there is a thing on the counter from BP that says about what happens to fuel as it ages, I only had a quick look but it just sounds like the octane rating gets higher.

I wasn't having a go at anyone over fuel/oil making them crook, if I get a small amount of fuel on me it affects my nerves really bad, REALLY bad. Same goes for any chemical.


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