Chainsaw with scored piston. How?

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I like chainsaws when they run... when they stop I upgrade to a new one. I've only had 8 saws in my life including my current Husky and a Poulan which I use for a backup. I've used a few others on various jobs; I loved my Partner 5000, even if I did almost take my leg off with it. Oh to be young and dumb again.

Loved the Pioneer saws. The 5000+ is still a sought after saw.

 

[ruffdog]

Back when, we never had chainsaws running as fast as they are now. The old McCullochs and Homelites I used to use were lucky to have chain speeds of over 8000 rpm.
With manufacturers making smaller saws with as much power as the old larger ones, speed is critical. The old saying "nothing beats cubic inches" is not quite true as rpm's can certainly over come c.i. deficiencies.
Old saws, being way slower, were much less susceptible to fuel ratios, gas quality or chemical configuration and poor or uninformed cutting techniques than exist today.

Back in my ice racing days, we would have multiple jugs of fuels mixed at different ratios so we could quickly "rejet" without having to pull the carb. Humidity and temps can change quickly on the ice so a fuel change was easy and quick. We were also running highly tuned engines vs what is found in common trail machines. Same goes for our saws today.....you can't compare them to 70's-80's saws that were slow and heavy.

 

[Oldpath05]

This guy knows what it's like to fix a saw, he's fast to>>> Seized 196s Chainsaw Restoration - YouTube

 

[Deere Dude]

2013 Stihl MS 362 with 18 inch bar; ...Then he said must have overheated. $500 repair on a $725 saw. I'm pissed as ****, but don't know what to do. e.

I would look at it this way, would I buy a 5 year old MS 362 saw from a shop or ebay for $500? Probably not. Maybe $300 or so. So I can't see sticking $500 on a bum saw.

Two years ago it was a toss-up between a MS 362 and a Echo a CS 620P and I got the Echo as it was considerably cheaper. Strong, starts very easy for a 60 CC and recommended up to a 24"bar I think.

Good luck with your saw, but that is exactly one thing I was dreading. Buy an expensive saw and have it crap out soon and now face the ball buster.

 

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This guy knows what it's like to fix a saw, he's fast to>>> Seized 196s Chainsaw Restoration - YouTube

Very skilled guy who apparently has done this before. I wonder if he had hair on the back his hands before he decided to stick his bare hands in all kinds of chemicals.

 

[Bigfoot62]

Buxus,
Sorry to hear that you had problems with that saw.
I love Stihl saws and that's all I run. (as well as string trimmers and blowers)

I'm not a mechanic or engineer, but the only way I know of to score a piston on a 2-stroke engine is insufficient lubrication. As Ruffdog said, that could have been caused by various issues, (carb adjustment, vacuum, ethanol, etc) but the results are the same: Metal will stick together when it gets hot and doesn't have proper lubrication. I only use non-ethanol gas and Stihl premium mixing oil. Never had a problem with that. In fact, my oldest saw, a Stihl 025, is 30 years old. Never been overhauled and I just used it two weeks ago.

You mentioned that you might just buy a "cheap" saw next time. I think you'll be disappointed if you do. "Cheap" saws are probably fine for people that don't actually use them! But for those of us that depend on a good tool when we need it, quality matters.

 

[ericm979]

Overheating or running lean will score a piston too. The piston crown will show damage in those cases.

 

[Buxus]

Follow up: About 4 weeks ago I finally found time to bring the chainsaw to my usual dealer. He looked it over, could find no obvious reason for overheating. He felt the most likely culprit was a carburetor that needed adjusting. He took a look at the cylinder, and he felt he could clean it up enough that it would not need replacing. He ordered a new piston, which took a while to come in. He adjusted the carburator to allow for a richer mixture, and replaced the piston. So far works great. $209. I am pleased. Thanks for all the help from all the posters on this site.

 

[ArlyA]

Thanks for the update!

 

[ericm979]

The correct carb adjustment changes with the ambient temperature. Set it when it's hot and it'll be too lean when it'd cold. Set it when it's cold and it'll be too rich when it's hot. Changes in altitude also affect the carb.

I adjust my carb saws at least a couple times a year. The M-tronic ones just work.