bad bearing?

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Megunticook

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Was out bucking a maple tree yesterday with my Husqvarna 55 Rancher I've had since I bought it new in 2004. Generally runs great, although I did have to replace the cylinder and piston a few years ago after it lost compression.

So the saw chain seemed like it got pinched at one point, I pulled the saw out of the cut, and then it stalled. When I tried to restart it I pulled once and then the next pull everything seemed to lock up. I let her cool down then brought her to the bench for a closer look. Still didn't want to crank at all, I removed the sparkplug, the muffler (so I could see if the piston was damaged/burned), the bar/chain, and the starter assembly, I was able to turn the crank but it seemed like it wanted to bind at top dead center. No sign of damage or burned areas in the part of the piston I could see.

The main bearings have never been replaced in this saw. It cuts 2-3 cords of firewood every year. You think it's time for a complete rebuild? Or is something else going on here?

Should I just tear it completely down at this point? I don't have a backup and am right in the middle of processing next year's firewood, so would love not to have a lot of down time, but maybe I don't have a choice here.

Thanks for any advice.

55-rancher.jpg

saw-powerhead.jpg
 
Already pulled the starter assembly. Pulled the carb and took a peek into the cylinder intake, it looks to me like part of the piston is missing from the bottom edge of the piston to part way up the sidewall there's a wedge-shaped area where the metal is missing. So...piston failed and the fragments jammed things up?

I'll pull the cylinder and have a closer look. Why would that happen? I replaced the factory piston/cylinder with an aftermarket about 6 years ago.

Overheating? Cheap parts?
 
Already pulled the starter assembly. Pulled the carb and took a peek into the cylinder intake, it looks to me like part of the piston is missing from the bottom edge of the piston to part way up the sidewall there's a wedge-shaped area where the metal is missing. So...piston failed and the fragments jammed things up?

I'll pull the cylinder and have a closer look. Why would that happen? I replaced the factory piston/cylinder with an aftermarket about 6 years ago.

Overheating? Cheap parts?
6 years on an AM piston? You got more than you money's worth. OEM piston would likely still be running. Now you have to worry about collateral damage to the cylinder, crank and bottom end bearings.
 
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