Removing seized piston

**mad_max** · 28th April 2010, 13:37

Im looking at buying a 97 YZ125, He said its got a seized piston but It will come out. I dont know about this sort of stuff too well but got some M8s that do. is there a way I can tell on the spot weather it will come out or not? and whats the easiest way to remove it?

Its cheap but dont really want to blow money on it and find out it wont come out and fork out heaps more to get it going

Need help!

**motorbyclist** · 28th April 2010, 14:29

Originally Posted by mad_max

Its cheap but dont really want to blow money on it and find out it wont come out and fork out heaps more to get it going

you've answered your question right there. In over a decade of biking off and on road the most important thing i've learnt is don't buy a bike with a major seizure in it's history unless you know the guy who seized it, even if it's been fixed. I've seen 250 sports bikes with "brand new pistons + rings + valves" break it's crankshaft just three days after purchase, bikes with total engine damage from running without oil or coolant, and countless cases of people selling their problems onto the next poor fool, and in some cases not mentioning that the bike was damaged at all. never buy unseen and always buy in good condition unless you're looking for a project.

if the piston is stuck there's not much you can do that doesn't involve a large hammer and a block of wood. It's likely welded itself to the cylinder lining or has jammed on the exhaust port. Or both. this could have bent the crankshaft, damaged any of related bearings, or not. Gamble as you like.

**Katman** · 28th April 2010, 14:31

I imagine the piston will come out easy enough but goodness knows what the bore will be like.

**AllanB** · 28th April 2010, 15:22

Had one years ago on a old shitter. Popped the head and squirted a load of CRC in the top of the bore and left it for a week. A tap with a bit of wood and a hammer released it. Then you need to check all the other connected parts below the piston ............

**mad_max** · 28th April 2010, 16:05

Yea hes got it at a shop at the moment and hasn't picked it up yet so I emailed the shop to ask them to tell me the condition of everything. It is a kind of project but no one I want to fork out loads for. Im hoping the shop will email me back because the guy could say anything and hopefully the shop will tell me what I need to know.

Heres hoping.

If its not cheap to fix Ill just put another motor in the frame. Ive got an older YZ 125 that I could mount that motor into it because the frames all in good condition