Paid $75 for a stihl today that didn't run. I pulled the muffler before I bought it and it looked ok. Also pulled it to start it and it was free.....thought it would need a tune up. Well after further inspection the piston is damaged as is the cylinder. I took some pics and tried to clean it to show the damage. I will upload them later. Not sure what happened on this one I could not see the damage because it's on the sides of the piston. Only noticed it from looking down spark plug hole after I got home. Both sides of the piston have deep gouges that look identical
New stihl pickup may have got jipped.
- Thread starter rippinryno
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dougand3
Minister of Fire
dougand3
Minister of Fire
That sucks that piston is trashed. The AM parts machine isn't as prevalent for the MS270. If it's only the P&R, a Golf kit costs ~$30. I don't know if they are any good, tho.
Does it have a decompression valve on it? I wonder because on my MS390 the decompression valve came apart and some of it fell on top of the piston, luckily I discovered it before it did any damage. Just a thought.
Randall
No decomp valve. I find it weird that the marks are identical on both sides on the piston but the exhaust and intake are fine. The ring gap pins are still in the piston and the rings are all in tact except there the gouges went through. Very weird. I double checked to make sure the ring gap tapers are facing down...is that right? I can't recall off hand if they taper down or up?
dougand3
Minister of Fire
Usually the pin is at the top of the ring groove, so the ring is longest on the bottom. So, you could say...the taper curves upward. But it's easy to answer "is this correct?" upon eyeballing it. If the ring is upside down, it won't seat because the long ends of taper will be on top of the pin.
Sconnie Burner
Feeling the Heat
I would guess maybe the pin retaining clips have come loose. That would be my only guess as to why it's on the sides opposite the intake and exhaust only. Possibly been rebuilt before and they were intalled incorrectly? I remember reading somwhere where stihl or husky had a manufacturing issue where the ring clips wouldn't stay put also.
jb6l6gc
Minister of Fire
Maybe pick up a cheap compression gauge and bring with you in future. I've done that when buying things second hand. Has saved me from a couple bad ones !
Thanks guys yeah I am gonna try to rebuild this one but it looks like aftermarket is about $80 for piston cylinder so I'll be in it 155
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