Hey guys I tried to install my new piston on a 1998 rm 250 (stock bore) and when sliding the head on the rings somehow got messed up by the intake near the reeds. I used tons of premix to lube it up nice, but it got stuck and bent the heck out of my new rings. I don't know what happened, the bore is clean and they were aligned properly. Any tips for next time so I don't make another $30 mistake? :bang:
What he said? If you twist that cylinder ever so slightly, to align with the base studs, you are screwed. The other is that the piston is facing towards the exhaust, backwards, it will snag a port.
Yeah somehow the 2nd ring snags the intake port. I'm using an OEM suzuki piston/rings, and i have the arrow pointing towards the exhaust... Never had such a hard time with any of my other RM's, what gives!?! In the process of bs the piston got a few small scratches but nothing you can feel with your finger, I can still use it right? Hopefully I can buy just one ring from the dealer!!!
The top of the piston, ideally does not touch the cylinder, but hanging the ring is a concern. The ring pin did not get pushed in? I would think that the cylinder was not aligned when it dropped onto the studs, even partially off center of stud?
I think that was the problem, we were having a hard time getting the head to clear the studs. It seemed to go into the bottom fine, but got hung up on the intake port! What can I do to make sure I don't do this again?
Just to clarify, you get just the jug in as high as you can get it, then push the piston up into it/slide the jug down to the base studs? Then put the head on?
Was it the ring "end" that got hung up? As mentioned, first be sure ring-end-gap's are lined up with locating pin (piston will slide in easy) and do NOT rotate cylinder to align with studs (will catch a ring "end" on a port.)
I don't know if this would help but I've put the piston in the jug first and then slid the wrist pin in place. By putting the piston in the cylinder first you have a lot more control with it.