Piston scoring.

[M&Rtree]

So today was a rainy day so I decide to do a muffler mod on a great running saw. I pull the muffler off and see some scoring on the piston. What should I do? This saw runs really great and seems to have great compression. The ring looks ok and is not stuck. If you hold the pull cord it takes awhile for the saw to drop, also the saw idles and revs perfect.

 

[hamish]

Most likely just carbon scoring, what does your exhaust port look like?

 

[ELECT6845]

Pull the cylinder and install a new Meteor piston with rings. Why chance trashing the cylinder?

 

[splitpost]

any pics ?

 

[M&Rtree]

Most likely just carbon scoring, what does your exhaust port look like?

Now that you mention it the exhaust port was pretty black. Will carbon build up prematurely wear the cylinder out? When I first received the saw it had a rich tune up.

 

[M&Rtree]

I can take some tomorrow. I'd really hate to pull it apart it just runs so dang good.

 

[hamish]

Now that you mention it the exhaust port was pretty black. Will carbon build up prematurely wear the cylinder out? When I first received the saw it had a rich tune up.

Eventually yes, as it is abrasive. Usually if the saw is running good a quick clean up and your good to go again.

 

[Clarkbug]

First saw I ever bought had some carbon scoring. I leaned it out, ran Stihl Ultra in it, and it hasn't given me any problems. I Haber a new piston for it that I'll put in once I have time, but I have no qualms about running the saw in the meantime. Its cut a lot of wood for me since I bought it...