aboekman
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Yeah, it looks good.
Can you diagnose my Stihl by listening to it?
- Thread starter aboekman
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Piston is boogered on the exhaust, that is aluminum transfer marks.
Looks like the same on the intake side.
Looks like the same on the intake side.
Piston is in upside down 
aboekman
ArboristSite Lurker
How do I unbooger it?
Clean the transfer off the cylinder walls and replace the piston and rings.
But that’s not why the engine cuts out at upper rpm’s
Harley comes through again!!!
Time to take off P/C. If can you do a vac/pressure test first, then clean it up, and take off clutch and flywheel.
Start checking ebay for NOS/OEM pistons..........
Time to take off P/C. If can you do a vac/pressure test first, then clean it up, and take off clutch and flywheel.
Start checking ebay for NOS/OEM pistons..........
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The ladies say that it is pretty big.....
aboekman
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Thanks again all. I didn't fix it but I did learn a lot. Think I should replace the coil?
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No, not with piston damage.
It is the same coil as the one on the 029/ms290,
lots of good used ones around.
It is the same coil as the one on the 029/ms290,
lots of good used ones around.
SteveSr
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Piston has definitely been scored by the video. I am surprised that it starts and runs at all.
However, I can't correlate the symptom to the piston damage unless the piston starts to get warm and then re-seizes, slows down and cools off. Rinse and repeat. May still be a coil issue and if found to be bad could have possibly caused the piston damage by mucking up the timing.
BTW, what is the history on this particular saw?
SteveSr
Addicted to ArboristSite
Buy a new one! You'll may or may not also need a new cylinder to go with it depending on the damage. However, since it still runs the cylinder is probably salvageable.
Don't run it anymore until the P&C is replaced/repaired. All you'll do is transfer more aluminum to the cylinder that will have to be removed later.
OP replace the plug ,look for chaffed or loose wires ,swi and if all fails bad coil is suspect.
Right now it needs a rebuild with piston, rings ,seals,cleaning up of the cyl and a coil.
aboekman
ArboristSite Lurker
Sheesh, might be time for a new saw.OP replace the plug ,look for chaffed or loose wires ,swi and if all fails bad coil is suspect.
Right now it needs a rebuild with piston, rings ,seals,cleaning up of the cyl and a coil.
Yup could be.
I don't think that piston is bad
If the timing has been advanced to much,they cut out at high revs.
Check the keyway for slop,and or signs of a slight shearing (as austin powers would say)
Check the keyway for slop,and or signs of a slight shearing (as austin powers would say)
SteveSr
Addicted to ArboristSite
This is known as a "project saw". If you are mechanically inclined you could probably rebuild it. 026's are now pretty old, like 3 generations, but were (and can be again) great professional grade saws.
If I had this saw it would be stripped, all critical rubber replaced, crank seals replaced, and anything else that you find fixed. Parts common to later generations (MS260) are still mostly available. 026 specific, like plastics, probably not unless you can find it used.
SteveSr
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How old is your glasses prescription? Time for a new pair?
