# Is milling hard on a chainsaw?



## sachsmo (Jul 17, 2011)

Started an oil thread in the chainsaw section, it just pizzes most of those guys off. We all know milling is extremly taxing on a saw .Is there an oil (mix) that would be all that much better for the rigors of milling?


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## smokinj (Jul 17, 2011)

I run 40:1 in the 880 milling. Cross cutting your dont in the cut all that long. A min. would be a very large run. Milling 5 min's would not be uncommon. Lots of awesome cross cut saws would go KABOOM just running wot hot lapping it.


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## rarefish383 (Jul 17, 2011)

I run between 32 and 40 to 1. My dedicated fuel can is 32:1 and the can I use for every thing else is 40:1. I keep all the other stuff at 40:1 just in case my milling can is empty and I have to grab the other one. The other thing people just don't realize is milling is much dirtier than cross cutting. I'm having the devil of a time keeping fine powder like dust out of the carb box. I'm looking at making an air filter useing a piece of molded right angle hose clamped on the carb throat into a K&N car filter. One of the 6" ones, Joe.


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## sachsmo (Jul 17, 2011)

Air filtration is always a bugger when milling, made these bases and lids to fit the V stack with old air compressor filters that were laying around.


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## lone wolf (Jul 17, 2011)

sachsmo said:


> Started an oil thread in the chainsaw section, it just pizzes most of those guys off. We all know milling is extremly taxing on a saw .Is there an oil (mix) that would be all that much better for the rigors of milling?


 
In my opinion you should just richen up the main jet and give the saw time to air cool while running .also low octane pump gas makes it run hotter too.Use the premium.I use Stihl synthetic oil in all my saws none smoked yet when I run them.I also do not like to breath all the fumes when milling brutal on the lungs.


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## glennschumann (Jul 17, 2011)

*Is it so?*

I guess I have some questions and opinions on the matter of how hard milling is on a saw...

One question (Maybe BobL can help here) is once a saw is warmed up how long does it take for the exhaust temp (or cylinder temp) to level out when milling? I.e. When does the saw reach its maximum operating temperature? 30 sec, 1 min, 5 min, 10 min? If the temp keeps rising over time, then I'd say extended runs are to be viewed with caution, if it plateaus in 2 minutes, I'd say anything beyond 2 min isn't going to be any worse for the saw, as a saw is certainly designed to run that long without excessive wear and tear.

I also have a TS-400 cutoff saw, and I know that these can be bolted to a cart and run continually for scoring / cutting concrete and I don't know that to be any worse for the saw. Stihl designs these saw to be run like this I assume. Is there that much difference between the two (besides filtration)?

In terms of filtration, the dust produced by a saw milling, is more likely to plug / bypass the filter, thereby causing damage to the saw or poor performance so in this sense, I think milling exposes a saw to more potential damage... so be particularly dilligent about keeping the filter in shape and sealed. (Fuel and oil filters too)

When milling, we tend to run our saws for extended periods of time, perhaps a longer % of our visit to the milling site, vs. a fire wood cutter (perhaps). Just by running a saw longer, we are more likely to break, or uncover problems with our saws than somebody who does not run them as many hours. We may dull chains faster use more oil / fuel, plug our filters, wear out seals wiggle bolts loose, break recoil springs etc., hence it seems that milling is hard on saws, but perhaps as a function of problems per hour of running, we may just be average.

In terms of fuel, my opinion (just that) and what I run is 1:50 Ultra in all my saws. I do rinse out the little bottle with fuel to make sure I get all the oil, but I don't adjust my mixture. My view is that the 1:50 mixture is the lubricant, not the oil itself. Some smart engineers at Stihl figured this out, and I'm not as smart about these things as they are. Gas is a lubricant, but not a very good one for saws. Straight 2 cycle oil is a lubricant, but not a good one for saws. Gear lube is not a better lubricant than 5W30 because it is thicker / less diluted... it is just better/worse in certain applications. I apply the same thought process to 2 cycle mix, more or less. 1:50 is what I run.

I also do not run my carbs "rich". I run them properly tuned for cutting. While more fuel may be more lubrication and result in lower operating temperatures, the resulting work is less efficient, and requires more fuel to complete ( and more run time = more wear [and more emissions]). To my knowledge, vehicles and other large equipment is not "detuned" to increase longevity when put into extreme loads (full dump trucks etc). I do understand that engine management systems can optimize all sorts of parameters to extract the most power out of an engine without overheating / causing emissions etc, but for this argument, we are talking about engines without computerized engine management systems.

So, for what it is worth, I run 1:50 Ultra, and a properly tuned saw for all my work, and have had no problems. I am dilligent about keeping my equipment clean (filters in particular) and stop at the first sign of trouble (e.g. when saw won't idle down). This may not be the most common opinion, but this isn't the first I've "gone against the grain", so I'm open to hear arguments against the above to better educate myself.

Schumann


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## SDB777 (Jul 17, 2011)

The original question...."Is milling hard on a chainsaw?"


It'd be harder without one



So what did I win?
It's not really that hard on one if you take the correct precautions.

Scott B


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## pwoller (Jul 17, 2011)

32 to 1 with the best ethanol free fuel you can get. As others stated before I let my saw cool on long cuts and also after each cut if the wood is smaller.


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## 820wards (Jul 18, 2011)

sachsmo said:


> Started an oil thread in the chainsaw section, it just pizzes most of those guys off. We all know milling is extremly taxing on a saw .Is there an oil (mix) that would be all that much better for the rigors of milling?


 
Milling is tougher on your saws, ditto on everyone on maintaining your saw, ie. filters, plug inspections for lean or rich mixtures. I run my big mill motor, 134cc at 32:1 and have not had problems with heat or fouling plugs. Also be sure to flip our bar regularly to wear it evenly on both sides and to maintain it's edges on both sides. My mill clutch drum has needle bearings, so after I take the chain off to sharpen, I remove the drum and grease the bearing. Do your maintenance at home and you will have a great time in the field. 

jerry-


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## BobL (Jul 18, 2011)

glennschumann said:


> I guess I have some questions and opinions on the matter of how hard milling is on a saw...
> 
> One question (Maybe BobL can help here) is once a saw is warmed up how long does it take for the exhaust temp (or cylinder temp) to level out when milling? I.e. When does the saw reach its maximum operating temperature? 30 sec, 1 min, 5 min, 10 min? If the temp keeps rising over time, then I'd say extended runs are to be viewed with caution, if it plateaus in 2 minutes, I'd say anything beyond 2 min isn't going to be any worse for the saw, as a saw is certainly designed to run that long without excessive wear and tear.



Unless the cut gets noticeably narrower (eg you mill up the log) or the chain hits a patch of pukey wood, if a constant forward force is applied (eg slope milling) I found the temperature never really plateaus but rises quickly and keeps increasing slowly during the cut. This is because the chain gets blunter and the saw has to work harder. Some of my cuts in 40"+ wide aussie hardwood can take 20 minutes. The temp gauge is very useful to see what is going on in these long cuts. There is also a natural tendency to want to finish the cut asap so the operator tends to push harder at the end than the beginning and that also increases the temperature significantly. I can push harder and watch the temp gauge increase in about 3-5 seconds. Using or not using aux oil also affects the engine temp. 

In terms of temperature what most operators do not realize is how long it takes a hot saw to cool down. 
As soon as the saw stops cutting the temp as recorded by my gauge (in contact with the outside/top of the exhaust manifold shoots up for about 15-20 seconds as the engine cannot be cooled fast enough by the fan.
After a long hard run it takes ~ 5 minute to get the engine back to initial idling temp (which depends on ambient temp). I used to only cool it 30 seconds but what I was doing more recently was let it idle till for maybe 2 minutes at the end of the cut.



> I also have a TS-400 cutoff saw, and I know that these can be bolted to a cart and run continually for scoring / cutting concrete and I don't know that to be any worse for the saw. Stihl designs these saw to be run like this I assume. Is there that much difference between the two (besides filtration)?


There is a difference, cutoff saws don't go anywhere near as blunt in cuts as chain does. I don't have a lot of experience with cutoff saws but my understanding is once the cutting edge is gone, its gone and pushing just doesn't do anything 



> In terms of filtration, the dust produced by a saw milling, is more likely to plug / bypass the filter, thereby causing damage to the saw or poor performance so in this sense, I think milling exposes a saw to more potential damage... so be particularly dilligent about keeping the filter in shape and sealed. (Fuel and oil filters too)



Maybe it's because I mill mostly green logs but I cannot think of one example where I cleaned a dirty filter and noticed a difference in temperature. I usually only clean my filter at the end of a day of milling green logs and maybe 2-3 times during a dry log milling day. However I do always try to mill with the wind at my back and on the 880 (and to a lesser extent the 076, the modified exhaust blows the sawdust well away from the saw. On the 880 I never have to walk in more than 1/2" of sawdust while milling even a biggish log. 

Most of the problems with too much dust on the filter of a milling saw I have seen on other peoples milling saws seem to me to be related to chain sharpening issues and making dust versus chips. Mostly they just don't touch up often enough or their rakers are too high (ie don't use progressive raker setting).

I agree with you on using the 50:1 with fully synthetic if the saw is kept well tuned and the mix is made carefully every time. I use 40:1, highest octane premium gas, and non-synthetic, mainly because I find it hard to get synthetic, and the 076 is speced at 40:1 and I don't want to continually keep a range of mixes for different saws. If I had access to synthetic I would probably use 50:1 even with the 076, I think BlueRider does this.

In practice cooking a saw is the sum of a bunch of factors and it's when these align that problems arise. For newbies and folk with lackadaisical attitude or limited skills in things mechanical I always recommend 40:1. For mechanically skilled operators they could probably mill successfully at 60+:1 using synthetic and high octane premium. 

As for tuning, its one of those factor it's best not to be wrong about so I prefer to err on the side of caution and drop the max revs a few hundred rpm. I like to see the plug on the darker side of medium brown (hard to do because the idle cool down changes the colour) but I will occasionally stop the saw after 5 minutes in the cut and check the plug.


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## pwoller (Jul 18, 2011)

BobL said:


> Unless the cut gets noticeably narrower (eg you mill up the log) or the chain hits a patch of pukey wood, if a constant forward force is applied (eg slope milling) I found the temperature never really plateaus but rises quickly and keeps increasing slowly during the cut. This is because the chain gets blunter and the saw has to work harder. Some of my cuts in 40"+ wide aussie hardwood can take 20 minutes. The temp gauge is very useful to see what is going on in these long cuts. There is also a natural tendency to want to finish the cut asap so the operator tends to push harder at the end than the beginning and that also increases the temperature significantly. I can push harder and watch the temp gauge increase in about 3-5 seconds. Using or not using aux oil also affects the engine temp.
> 
> In terms of temperature what most operators do not realize is how long it takes a hot saw to cool down.
> As soon as the saw stops cutting the temp as recorded by my gauge (in contact with the outside/top of the exhaust manifold shoots up for about 15-20 seconds as the engine cannot be cooled fast enough by the fan.
> ...



Bob I'm curious what the benefits are of running 60 to 1 over 40 to 1?


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## BobL (Jul 19, 2011)

pwoller said:


> Bob I'm curious what the benefits are of running 60 to 1 over 40 to 1?



In terms of engine operation I cannot think of any advantage. The difference between the amount of gas in a 60:1 to say 40:1 mix is small ie (40/41 -60/61)*100 = 0.8% which is less than the variation one would see in tuning around the max RPM point with the H screw and or atmospheric pressure so it will make little difference in performance or cooling.

One advantage I can think of is the less two stroke oil that is burnt the better the surrounding atmosphere is for the operator. Two stroke oil is full of gunk and the manufacturers are very good and adding smoke suppressants to make the smoke invisible but that just makes the smoke particles finer so they cannot be seen. That's why I am opposed to running say 25:1, which I have tried and it always gives me a headache. Longe term who knows what is happening.

BTW: I'm not necessarily advocating using 60:1 - I advocate using what the manufacturer specifies. I'll leave it to someone else to demonstrate that 60:1 or 70 or 80 : 1 works on a long term basis.

I also re-read glennschumann post and do have a difference of opinion or explanation for this.


> . . . . . To my knowledge, vehicles and other large equipment is not "detuned" to increase longevity when put into extreme loads (full dump trucks etc). . . .


CS are very different beasts from just about all other internal combustion engines in that they are designed to run WOT for their entire life. Imagine how long any other internal combustion engine would last if it were run at WOT? What would be the easiest and safest way to get more life out of an engine that already operates at WOT and is being used under conditions for which it was never designed ? It's simple - reduce the max RPM they operate at. The easiest and safest way to do this on a CS is richen up the air fuel mix.

No stock chainsaw has ever been designed to operate under the continuous WOT loads imposed by CS milling. If a CS dies under warranty and the servicing people find out it was being used for were milling with it they can and sometimes do refuse a warranty claim. Detuning to dump a little more fuel into the saw is purely a precautionary measure. If it is a really still hot day, the chain is blunt, the airfilter clogged and you messed up the mix ratio slightly then your last bit of protection is a slightly detuned saw. Even with with regular chainsaws I have seen one, and known of several other, CS die when the they were used under the same trying conditions as well as being used in a confined space so that insufficient air could not reach the fan.


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## BlueRider (Jul 20, 2011)

I have been milling with a chain saw since 1994 and for the majority of that time I used an 051 running 50:1 mix. A vew years ago I switched to a 075 and I run 50:1 in it too. I am a huge fan of Stihl HP Ultra. 

I always warm my saw up before I start milling and I let it idle for a couple of minutes after cutting a slab. 

I think the hardest thing on a milling saw is trying to mill too wide of a log with not enough cc's.


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## Timberframed (Jul 20, 2011)

I run 25:1 manufacturer rec. for stock Oleo Mac 999 concrete/stone saw. No internal oiler but aux is a must on a 60" bar anyway. A benefit here might be that as the saw warms up so does the oil in the reservoir which we all know that hot oil takes a bit to cool down to ambient. Saw was designed to run wot 24/7 as in rescue demo and all day long on the job. Bare handed handling after a 30 min run through 55" hardwood never felt too hot a saw. I don't wait for the fuel to run out. I top off every 10 minutes in the cut. Gots to get me one of those temp gauges just out of curiosity.


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