imagineero
Addicted to ArboristSite
Few months back I posted this thread about a piston stuck in cylinder
https://www.arboristsite.com/community/threads/441cm-piston-stuck-in-cylinder.317717/
It sat on the shelf for a while till I got to it last week and split the case to try to get at it a little better, where I discovered the flywheel side bearing had not so many bearings in it as it ought to. in light of the time that's lapsed and the new information I figured it would be better to start a new thread.
The missing bearings were not inside the crankcase, so it's a fair bet at least one of them got sucked into the jug. Surprisingly, the jug appears to be in good condition from what I can tell looking through the plug hole. what looks like scratches in the photos is just some shelf muck that's stuck to the oil.
So, the piston appears to slide all the way up to TDC (or at least very close), and slides down about 9/16" where it doesn't want to go any further. I haven't forced it in any way. If you're looking up to the cylinder from the bottom, the piston/crank can be rotated about 1/8 of a turn counterclockwise at TDC, and only a couple degrees clockwise. In the lower position it rotates almost a full quarter turn counter clockwise and again only a degree or two clockwise. It seems to follow the shape of the skirt/window a little as it's rotated, you can feel something.
This pic from below shows the intake port when it's as up as it's going to get. Again, the stuff on the cylinder walls is just dirt.
And this one shows how far down she comes from the exhaust port; lower piston ring comes into sight.
So.... I'm open to any ideas. I'm guessing a bearing or maybe part of a ring caught in the transfers. Could try maybe welding a zerk to a plug and grease gunning it out? Would be nice in fantasy land to imagine that I could salvage the whole lot, but if anything has to be damaged it would hopefully be the piston. Jugs are $$$ in australia (about $800 from memory) and pistons are only $. I could use the crank in another saw, or in the same saw. No idea what other damage is done, maybe piston slammed into top of jug, crank bearings probably shot, maybe crank too.
Open to you guys.
https://www.arboristsite.com/community/threads/441cm-piston-stuck-in-cylinder.317717/
It sat on the shelf for a while till I got to it last week and split the case to try to get at it a little better, where I discovered the flywheel side bearing had not so many bearings in it as it ought to. in light of the time that's lapsed and the new information I figured it would be better to start a new thread.
The missing bearings were not inside the crankcase, so it's a fair bet at least one of them got sucked into the jug. Surprisingly, the jug appears to be in good condition from what I can tell looking through the plug hole. what looks like scratches in the photos is just some shelf muck that's stuck to the oil.
So, the piston appears to slide all the way up to TDC (or at least very close), and slides down about 9/16" where it doesn't want to go any further. I haven't forced it in any way. If you're looking up to the cylinder from the bottom, the piston/crank can be rotated about 1/8 of a turn counterclockwise at TDC, and only a couple degrees clockwise. In the lower position it rotates almost a full quarter turn counter clockwise and again only a degree or two clockwise. It seems to follow the shape of the skirt/window a little as it's rotated, you can feel something.
This pic from below shows the intake port when it's as up as it's going to get. Again, the stuff on the cylinder walls is just dirt.
And this one shows how far down she comes from the exhaust port; lower piston ring comes into sight.
So.... I'm open to any ideas. I'm guessing a bearing or maybe part of a ring caught in the transfers. Could try maybe welding a zerk to a plug and grease gunning it out? Would be nice in fantasy land to imagine that I could salvage the whole lot, but if anything has to be damaged it would hopefully be the piston. Jugs are $$$ in australia (about $800 from memory) and pistons are only $. I could use the crank in another saw, or in the same saw. No idea what other damage is done, maybe piston slammed into top of jug, crank bearings probably shot, maybe crank too.
Open to you guys.
any advice how to fest go about it? Could I remove the decomp etc and put the jug in the oven and maybe melt the plastic?
