Hey guys basically fucked my bike up yesterday. (08 yz250f)

Just changed the oil the day before and mustn't have tightened the screw on the bottom of the oil tank. (I'm a dickhead I know)
So went for a ride...and about 500m down the road the bike pretty much just stopped on me. Then I saw the oil everywhere. First thoughts were it's seized, but now I don't think so.

I filled it back up with oil last night and after a bit of testing today the piston still turns over in 2nd, 3rd etc... but NOT 1st. It's also really hard to even select first.

Any ideas what the problem might be before I take it to the shop??

I dont think the 2nd and 3rd gear turning over and not in 1st has anything to do with it.

Could have chewed out the camshaft bearings/runners or bottom end. The cam is usually something that gets shagged first, due to the high speed it is moving.

gear box side or engine side?

Ahh ok then thanks. So not gonna be cheap.




What do you mean??

He means was it the oil from the gear box side, or from the engine side. Which oil was dropped?

The oil was spilt through the bolt on the bottom of the oil tank thingy you can see in the pic.

Just incase anyone was wondering it turns out the piston rings melted to the piston.

nice job lol xd gl with getting it all up and gud again!

All fixed now

Here's the old barrel and piston.
Sorry for the shitty camera phone pics too lol.

hahah neato!


How to fuck in a piston in one easy step starve it of oil!@