Toasted my clone ms660 on amsoil at 100:1

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This is a pretty cool thread to me - just for reading entertainment on this snowy inside day.

I like the OP's attitude - seems to have a smile on his face even while typing!

For someone like me, (who's never going to do much more than a muffler mod) had I went to the trouble to build one like he did, I would have handled it with extreme care for some time.

The OP on the other hand is obviously talented in this area and it just isn't that big a deal to him - he tried it, it didn't pan out - he shrugged it off and fixed it up.

Boy I envy people who can work on stuff at this level....
 
This is a pretty cool thread to me - just for reading entertainment on this snowy inside day.

I like the OP's attitude - seems to have a smile on his face even while typing!

For someone like me, (who's never going to do much more than a muffler mod) had I went to the trouble to build one like he did, I would have handled it with extreme care for some time.

The OP on the other hand is obviously talented in this area and it just isn't that big a deal to him - he tried it, it didn't pan out - he shrugged it off and fixed it up.

Boy I envy people who can work on stuff at this level....
It's very satisfying when a re-build(or fresh build) pops after a few pulls.
 
I saw the same damage on a clone 440 running 50 to 1 , I run about 35 or 40 to 1 , I also tell all my customers at work, we are a Stihl dealer, to do the same thing some do some don't, if they do I tune their saw on the heavy mix free of charge.
 
Jetting has an effect also do you realize that when tuning?

Yes, and I think the amsoil is relatively low viscosity stuff. Perhaps causing to run a touch rich in many applications. I'm going to stick with penzoil AC or Stihl HP. This is what I generally use and haven't had any issues at ~40:1.
 
Yes, and I think the amsoil is relatively low viscosity stuff. Perhaps causing to run a touch rich in many applications. I'm going to stick with penzoil AC or Stihl HP. This is what I generally use and haven't had any issues at ~40:1.
40 to 1 works for me in all mine. Just keep the H needle adjusted a bit on the rich side! I have not had this happen since my Husky 262 in the 1980's
 
Then on a whim I bought a bottle of amsoil and ran a tank at 80:1, seemed fine, thin oil.

Did you buy amsoil saber? It's quite thick not thin at all.
It's the only amsoil they recommend at 100-1, it's way thicker than dominator to pour so I can see needing less of it in the premix. I like amsoil but would stick to 50-1 with saber just to be safe.
 
Did you buy amsoil saber? It's quite thick not thin at all.
It's the only amsoil they recommend at 100-1, it's way thicker than dominator to pour so I can see needing less of it in the premix. I like amsoil but would stick to 50-1 with saber just to be safe.
I been using Amsoil at 40 to 1 for 6 years now, I am a Tree service in NJ nothing has failed from this oil yet and they all still have good compression. If stuff was seizing or hand grenading I may re think but It ain't gonna happen unless they change that oil or something. Watch out for cheap Ethanol gas it the biggest killer of everything most seem to overlook that.
 
Best explanation I've ever read about oil mix ratios was on a 2 stroke Moto cross forum. In the thread the guy explained that different two strokes operate on different power bands, a Moto cross bike while operating at high rpms most of the time are under load or operating in the upper power band 100% of the time so the mix ratios can be higher. A chainsaw where 99% of the time it's operating in the upper power band under load and sometimes heavy load need lower mix ratios to survive long term.

Sent from my E6810 using Tapatalk
Is anyone else confused by this? You're saying both are operating in the upper powerband under load but bikes can have a higher oil ratio?
 
I seen on you tube video where other kit saws like the Stihl clone seized from running the wrong ratio mix. This could be an ongoing problem.

When I assemble every piston and cylinder I pre lube it by burnishing in a moly paste. In the bore and on the piston skirt. I add a little two stroke oil in it too. In any engine I apply it to all the metal to metal contact moving parts. On the saws on start up I leave the choke on so the crankcase has a heavy mist of two stroke in it.

I also apply moly to the bar rails when installing a new b&c.

www.tsmoly.com
 
But I've also read that Euro specs on 80cc and up saws calls for 33 to 1, even though 50 to 1 is suggested for the same saws in the U.S.

Seems logical to me that a bigger saw would need more oil.

These comments are what make this site so worthwhile to me Helps me understand some of my previous frustrations with my 056 MagII Thanks for your insight
 
No doubt, I believe you are correct. My understanding is that in general being that the ms660 is of older design and large displacement, ~25:1 is probably the original intended ratio. Modern oils /are/ better than they used to be, allowing for thinner, maybe cleaner burning mix.
In anycase I'm thrilled with the 'kit' saw. This one was a gift, but I'd buy one for sure, I think it well worth the dime if your mechanically inclined. If I were to build another it would be the 200t, followed by a 361. I have a pair of real 361's that I do 75+% of my cutting with. I climb with a 019t that wont die, but I'd love to have a 200t.
The 660 is basically the best saw I have ever run. Thrilled.

I really have to disagree just a little. When I got my first McCulloch over 50 years ago and it was an old saw then we mixed at a ratio of 16:1 or 24:1 with 30wt non detergent oil. Yes there was always some smoke. Everyone liked the smoke because it was difficult to straight gas a motor. You knew exactly if there was no oil in the gas. Yes there was an issue about carbon build up in the motors. The carbon had to be cleaned every few years after heavy use, but not too big of a deal. More than 50 years latter saws are made better and oil is much better. What has changed, not that much. A two stroke motor can not experience high temperatures with minimum oil and live. I would say anybody can use any oil at 100:1 and make it work. However at high oil ratios there is very little room for any error even for 1 or 2 seconds. Some thing that most people overlook is the internal temperature of two stroke motors. When a two stroke is adjusted lean what happens. The internal temperature is the highest that burning gasoline can be. About 2000 F. If the mixture is adjusted more rich the temperature drops dramatically. So a combination of the right fuel mixture along with a good lubricant will allow a motor to live many years trouble free. Thanks
 
I really have to disagree just a little. When I got my first McCulloch over 50 years ago and it was an old saw then we mixed at a ratio of 16:1 or 24:1 with 30wt non detergent oil. Yes there was always some smoke. Everyone liked the smoke because it was difficult to straight gas a motor. You knew exactly if there was no oil in the gas. Yes there was an issue about carbon build up in the motors. The carbon had to be cleaned every few years after heavy use, but not too big of a deal. More than 50 years latter saws are made better and oil is much better. What has changed, not that much. A two stroke motor can not experience high temperatures with minimum oil and live. I would say anybody can use any oil at 100:1 and make it work. However at high oil ratios there is very little room for any error even for 1 or 2 seconds. Some thing that most people overlook is the internal temperature of two stroke motors. When a two stroke is adjusted lean what happens. The internal temperature is the highest that burning gasoline can be. About 2000 F. If the mixture is adjusted more rich the temperature drops dramatically. So a combination of the right fuel mixture along with a good lubricant will allow a motor to live many years trouble free. Thanks
I for one do not like breathing smoke! Anyone ever consider your lungs?
 

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