Hi everyone:
I'm not a small engine mechanic, but a handy home-owner. I have an FS550 that I bought used and that I'm using to try regain control of an overgrown acreage. After a couple of summers of great use, the compression was so low that it was really hard to start. The quote from my local dealer to replace the cylinder and piston seemed really high to me, so I did some research and found non-OEM parts online for pretty cheap and replaced them myself using a Stihl repair manual.
The saw ran perfectly for about 10 minutes, and I heard a small 'clunk', and it quit. It wouldn't start again, and when I tested the compression it was about 50. I ordered another piston and cylinder set, and installed them. The old piston had major gouges in it. It again ran perfectly for a few minutes, and then gave the same clunk and died. Same story again -- trashed piston. I've done this three times now, and I'm frustrated.
Here's my question: is it because the non-OEM (probably made in China) parts are so poor that I need to bite the bullet and buy the Stihl parts (which I'm happy to do), or is there something I'm missing when I do the replacement which would destroy the much more expensive Stihl piston and cylinder just as quickly as it has destroyed my non-OEM parts.
Any thoughts? I'm happy to buy the Stihl parts, but I'd hate for the same thing to happen again.
Thanks very much for any thoughts.
Harold
I'm not a small engine mechanic, but a handy home-owner. I have an FS550 that I bought used and that I'm using to try regain control of an overgrown acreage. After a couple of summers of great use, the compression was so low that it was really hard to start. The quote from my local dealer to replace the cylinder and piston seemed really high to me, so I did some research and found non-OEM parts online for pretty cheap and replaced them myself using a Stihl repair manual.
The saw ran perfectly for about 10 minutes, and I heard a small 'clunk', and it quit. It wouldn't start again, and when I tested the compression it was about 50. I ordered another piston and cylinder set, and installed them. The old piston had major gouges in it. It again ran perfectly for a few minutes, and then gave the same clunk and died. Same story again -- trashed piston. I've done this three times now, and I'm frustrated.
Here's my question: is it because the non-OEM (probably made in China) parts are so poor that I need to bite the bullet and buy the Stihl parts (which I'm happy to do), or is there something I'm missing when I do the replacement which would destroy the much more expensive Stihl piston and cylinder just as quickly as it has destroyed my non-OEM parts.
Any thoughts? I'm happy to buy the Stihl parts, but I'd hate for the same thing to happen again.
Thanks very much for any thoughts.
Harold