chip off 026 cylinder

[markvanzee]

chip off 026 piston

Got a freebie 026 that had very little compression. When i pulled the cilinder off, i found that the piston acctually had a chip broken off. On that side the piston sidewall has become very thin. Could this have caused the piston to start banging against the cylinder wall? Any thoughts about how this could have happened ? The other side of the piston has not worn off at all.

View attachment 260824
View attachment 260825
View attachment 260826

Planning to do a complete rebuild on this one.

 

[rob066]

Looks as though the rod hit the piston. Maybe somebody had hit the piston on the rod on a previous reassembly.

 

[TonyRumore]

Someone may have had the top end off, and then decided to remove the clutch or flywheel. The piston skirt was hanging over the side of the case when the crank was torqued on. It pulled the piston down into the case so hard, it busted a piece off. Just a guess....

Tony

 

[markvanzee]

Thanks for the replies, but the previous owner sayd it happened during cutting. I am the first to open this saw in many years.

 

[harrington]

if it happened while running and hasn't been opened until now then the remains of that piece should still be in the engine.

if it was done during and assembly then the broken piece was probably removed

 

[thomas72]

That saw has got some hours on it.

 

[ri chevy]

Better with photos to look at! Looks like it is time for a new P&C.

 

[blsnelling]

Your cylinder should clean up fine. It looks like all you need is a new piston. The skirt of the piston simply wore thin from use. You'll also notice how it allowed the piston to rock in the bore enough that the crown was hitting the top of the cylinder. Once the skirt was worn that thin, it simply fractured and broke. Make sure the filter isn't letting a lot of debris through. You need to carefully inspect all crank bearings as well. Seal replacement should be a given on this one.

 

[fearofpavement]

I had an 029 Super that broke a piece off the skirt from the piston wearing thin. Someone got lots of use out of your saw. Rebuild it and it'll last another couple decades.

I put an 039 top end on the 029.

 

[splitpost]

Your cylinder should clean up fine. It looks like all you need is a new piston. The skirt of the piston simply wore thin from use. You'll also notice how it allowed the piston to rock in the bore enough that the crown was hitting the top of the cylinder. Once the skirt was worn that thin, it simply fractured and broke. Make sure the filter isn't letting a lot of debris through. You need to carefully inspect all crank bearings as well. Seal replacement should be a given on this one.

just pulled one down thats done the exact same thing,just wore out with the help of years of ingestion,time for a complete build, it had 95psi and still ran but was guttless in the cut

 

[markvanzee]

thanks guys! i will replace the piston and seals bearing/ fuel line etc.