Blow up one piston, shame on Stihl. Blow up two pistons, shame on me. Blow up three pistons...?

[pepe_silvia]

if your going to be doing a lot of milling on big dia hardwoods, start looking at a move to stihl pmx chain, 3/8picco, a lot smaller kerf, an 050 gauge, and match it to a GB bars milling bar, uses a lot les power for the same cuts, screw your oiler up to maxand run the thinnest best quality chain oil you can afford, your fuel tank should empty just before your oil one, and on a 3' by 12' elm, 1 cut should be about 1 tank on a 660(sharp chain....very important)

Thanks for the advice. I'll try it out. I've had part of it right at least, had the oiler maxed and was filling both oil and fuel after every cut.

 

[big mog]

pepe, the best advice I can give you is get a chain grinder if your serious about milling, even after 40+ years sharpening chains, I still prefer the acuracy the grinder gives me.....every tooth is identical, every raker the same, it shows in the surface finish of the boards, I work with a 4 chain rotation, and run them equally, every time I buy a new set, I replace the sprocket, every 2nd to 3rd set, replace the bar, price your jobs appropriatly, and remember to cost in plenty of fuel and oil on the big timber jobs.....time?.....when someone gets a formula for working that out chainsaw milling, let me know...lol

 

[Blisters]

I

the more oil question........doesnt happen...DONT do it, set your saw up carefully

I've had some problems with tuneing a carb on a saw I built out of scraps leftover from 5 saws I got. its a 42cc poulan. I know a lot of ppl don't like em. I can tune nearly anything but this thing is a trip. I think I need to make smaller adjustments.

 

[BobL]

It's pretty common to hear folks referring to using lower gas/oil ratios as "running rich" - it's a wave that sort of comes and goes but never seems to die out.

Most saws will actually run safely on any gas/oil ratios between ~ 8:1 and 100:1.
Even the Stihl manual says if you don't use their Stihl 2 stroke lube you should run 25:1 (I won't go into why they do this here)
BUT
Whatever is used the saw MUST be re-tuned for that ratio.

Yes a saw will run and even mill quite safely on 100:1 (using a fully synthehic lube) which demonstrates how little oil is need for a modern saw.
However,r the reason the manufacturers recommend 50:1 is because it is very easy to stuff up making a 100:1 mix in small quantities - you only have to be a teeny weeny bit out and you end up mixing 150 or 200:1 and then the saw will be in trouble.

At less than 50:1 increasingly amounts of the lube just add more unburnt gunk like smoke suppressants into the air around the operator. This stuff is not good for you so will make more of it than necessary?

 

[KiwiBro]

Thanks for the advice. I'll try it out. I've had part of it right at least, had the oiler maxed and was filling both oil and fuel after every cut.

Good on you for rolling with the sanctimonious and uncalled for flaming from big mog long enough without objecting to reach a worthwhile point.

 

[lone wolf]

MS660. Was running a 42" bar on it this time.

Too lean of an air mixture or a vac leak maybe.

 

[pepe_silvia]

pepe, the best advice I can give you is get a chain grinder if your serious about milling, even after 40+ years sharpening chains, I still prefer the acuracy the grinder gives me.....every tooth is identical, every raker the same, it shows in the surface finish of the boards, I work with a 4 chain rotation, and run them equally, every time I buy a new set, I replace the sprocket, every 2nd to 3rd set, replace the bar, price your jobs appropriatly, and remember to cost in plenty of fuel and oil on the big timber jobs.....time?.....when someone gets a formula for working that out chainsaw milling, let me know...lol

I actually just picked up a grinder. It's the one here: http://www.northerntool.com/images/downloads/manuals/42595.pdf

More great advice, duly noted. Already figured out to price out my time: it's completely worthless.

 

[pepe_silvia]

if your going to be doing a lot of milling on big dia hardwoods, start looking at a move to stihl pmx chain, 3/8picco, a lot smaller kerf, an 050 gauge, and match it to a GB bars milling bar, uses a lot les power for the same cuts, screw your oiler up to maxand run the thinnest best quality chain oil you can afford, your fuel tank should empty just before your oil one, and on a 3' by 12' elm, 1 cut should be about 1 tank on a 660(sharp chain....very important)

Suggestion on where to pick up the GB milling bar?

 

[pepe_silvia]

Too lean of an air mixture or a vac leak maybe.

Sounds like I was running too lean. Hypothetically though, if it were a vacuum/air leak, how do I know that's happening before it's too late? What would make me say "I have a vacuum leak right now, I better stop cutting before I turn my piston into a molten blob"?

 

[DTrap]

You can tune a saw to run properly with whatever mixture you prefer. The problem is most people don't properly tune their saw when adding the extra oil causing a lean running saw. Which leads to the saw running hot and causing excessive wear on it. Todays saws will hold up well with a 40:1-50:1 mixture. Anything more and you are really just wasting oil and breathing in more of it as well. At least in the case of a milling application.

 

[pepe_silvia]

You can tune a saw to run properly with whatever mixture you prefer. The problem is most people don't properly tune their saw when adding the extra oil causing a lean running saw. Which leads to the saw running hot and causing excessive wear on it. Todays saws will hold up well with a 40:1-50:1 mixture. Anything more and you are really just wasting oil and breathing in more of it as well. At least in the case of a milling application.

By tuning the saw properly, you basically mean richen it until it 4-strokes, then lean it up a tad? Is there something else I should be doing to make sure I'm not too lean?

This saw had the limiters in it and I couldn't get them to turn far enough to start four stroking, so I just richened it up as much as a could. I'll know better next time.

 

[big mog]

i get mine from a guy here in the uk, chainsawbars.com, they are really good quality, he also does sugahara, but as of yet, I havent tried them, hes a first class guy to deal with

 

[pepe_silvia]

Since I'm here, any thoughts on 7 vs 8 tooth sprocket?

 

[DTrap]

I would stick with a 7. The 8 will give you more chain speed but less torque. It wouldnt really matter to much in small wood but on anything big it will bogg the saw down easier.

 

[Blisters]

Since I'm here, any thoughts on 7 vs 8 tooth sprocket?

Has anyone seen a lawn mower engine on a csm? Thought it was a lil slow, but it was a 4 stroke engine. My thoughts are like a 2stroke lawnboy would make a good one. What are your thoughts guys?

 

[ChoppyChoppy]

30:1 is rich..... 50:1 is leaner.....

No, more oil means less fuel which is lean.

 

[Mad Professor]

I always run my own mix. To the few I will lend a saw to, I give them my mix to use.

Going from 30:1 to 50:1 you will need to retune.

I retune if I change from 100LL to non-corn pump gas with the same oil ratio.

I've ran nothing but golden spectro in all my two strokes 45-50:1 since the 1970s and no oil/mix failures. Dirt bikes, saws, weed wackers........

 

[DTrap]

Well that's part of it. I'm by no means an expert but You should try to tune it in the cut. It should still 4stroke when not under load and then stop in the cut. Did you retune the saw when you switched to your buddy's 50:1 mix since you had tuned it for the 30:1 you were normally running.

 

[DTrap]

Well I guess Mad Professor beat me to it. I also will not use someone else's mix. I just don't trust people to properly mix it. If I didn't make it I don't use it. I also send my mix if someone is using my equipment.

 

[lone wolf]

Sounds like I was running too lean. Hypothetically though, if it were a vacuum/air leak, how do I know that's happening before it's too late? What would make me say "I have a vacuum leak right now, I better stop cutting before I turn my piston into a molten blob"?

It would not idle right for one thing. You my not notice a leak at full speed. A vac test should be done on this saw before you have another meltdown. Check the spark plug it should be tan not white after a hard run. Make sure the plug is the correct one for that saw. Are you using regular grade gas or super? Is your gas fresh from a high volume station or could it be old?