yawning_dog
ArboristSite Member
Zero dollar “fix” for scored piston/cylinder
Hi guys. I thought I would show you a little experiment I did on an 036. The saw was my father-in-law’s and he gave it to me saying it was hard to start etc. Well, he was right, but it did start after a while. It also seemed to idle okay and had good throttle response etc. But then I did one cut and the thing throttled down and stopped. Then there was no starting it again. Actually, I did get it started by holding it like a sword with my right hand, finger on the gas, and yanking on the starter like hell. I wouldn’t recommend this technique. But even then it wouldn’t idle at all. No carb adjustments would affect the operation.
So at that point I pulled the muffler and low and behold noticed that the piston was scored and the rings were stuck. Hmm, that could be a problem. I believe I measured the compression at about 110lbs cold. I decided to tear into it and see what could be done. For kicks, I decided to just clean up the cylinder and piston the best I could and put it all back together.
For the cylinder, I used muratic acid and a q-tip. I got it almost totally free of aluminum below the exhaust port as you can see from the pictures, but I probably didn’t do such a great job above the port. After that I used a ball hone on it. For the piston, I used a very fine grit wet sand paper to slowly remove enough material to get the rings out. This took some doing and it’s difficult because if you force them too much they’ll snap! I finally got them out and then I continued with the sand paper a bit in the affected area of the piston grooves etc. Finally, I cleaned everything off the best I could, put her back together, and fired her up.
I will say that it runs much better than it did. It’s not a 2 pull start though. It seems to have plenty of power, but the idle is pretty rough. Sometimes it will idle okay indefinitely, but sometimes it s..l..o..w..l..y dies. Low jet adjustments and the idle speed seems to affect it now, but I can’t say I’ve dialed in a setting that always works like a champ. That said, I haven’t really done more than a couple cuts with it either so I don’t know how it will act if it really gets warmed up and broken in. From the little use it’s seen, the saw shows about 130lbs of compression warm, which from what I’ve learned here is marginal at best.
Anyway, it seems like this is a hokey but reasonable technique to use if you don’t want to spend ANY money and you’ve got a few hours to mess around. Of course you’re not going to get a like-new saw out of it, but at least you’ll get some good garage time in!
Hi guys. I thought I would show you a little experiment I did on an 036. The saw was my father-in-law’s and he gave it to me saying it was hard to start etc. Well, he was right, but it did start after a while. It also seemed to idle okay and had good throttle response etc. But then I did one cut and the thing throttled down and stopped. Then there was no starting it again. Actually, I did get it started by holding it like a sword with my right hand, finger on the gas, and yanking on the starter like hell. I wouldn’t recommend this technique. But even then it wouldn’t idle at all. No carb adjustments would affect the operation.
So at that point I pulled the muffler and low and behold noticed that the piston was scored and the rings were stuck. Hmm, that could be a problem. I believe I measured the compression at about 110lbs cold. I decided to tear into it and see what could be done. For kicks, I decided to just clean up the cylinder and piston the best I could and put it all back together.
For the cylinder, I used muratic acid and a q-tip. I got it almost totally free of aluminum below the exhaust port as you can see from the pictures, but I probably didn’t do such a great job above the port. After that I used a ball hone on it. For the piston, I used a very fine grit wet sand paper to slowly remove enough material to get the rings out. This took some doing and it’s difficult because if you force them too much they’ll snap! I finally got them out and then I continued with the sand paper a bit in the affected area of the piston grooves etc. Finally, I cleaned everything off the best I could, put her back together, and fired her up.
I will say that it runs much better than it did. It’s not a 2 pull start though. It seems to have plenty of power, but the idle is pretty rough. Sometimes it will idle okay indefinitely, but sometimes it s..l..o..w..l..y dies. Low jet adjustments and the idle speed seems to affect it now, but I can’t say I’ve dialed in a setting that always works like a champ. That said, I haven’t really done more than a couple cuts with it either so I don’t know how it will act if it really gets warmed up and broken in. From the little use it’s seen, the saw shows about 130lbs of compression warm, which from what I’ve learned here is marginal at best.
Anyway, it seems like this is a hokey but reasonable technique to use if you don’t want to spend ANY money and you’ve got a few hours to mess around. Of course you’re not going to get a like-new saw out of it, but at least you’ll get some good garage time in!
