I'm going to look at an rm125 today after school that needs a piston and ring. He is only asking 500 so I thought it would be a good project. What should I look for seeing how I can't ride it. He is also taking the cylinder off so I can look in the motor. How much movement is normal for the crank arm? Anything else please feel free to chime in. Thanks

For $500 regardless of the crank condition I would snag it. for about 500 more you can have a brand new crank and bearings, topend and a good piece of mind. Just make sure the frame isn't cracked or the cases. check the cylinder for scoring if its scored you can have it replated for another $150.
Good luck

pull on the shifter lever and make sure it does not want come out of the case. thats an indication of alot of wear. make sure it goes threw all the gears. and check and see what the oil looks like-another indication of how the bike was treated.

and the rod can move side-to-side plenty, its the up-down pull thats bad. more than a hair of free play up-down and i would get a new bottom end. Seeing its your project bike better to do it right the first time.

i would check the wheel/swingarm/linkage/shock/ bearings. wheels can be checked up by wiggling. make sure the suspension is smooth, if it feels super slow to rebound or gets stuck the bearings are shot in the linkage/swingarm/shock somewhere. check the steering stem bearings to, if there is any play in the bars or if they are notchy when you turn the bars. like stated before, up and down play is bad. if its just pistons and rings thats a pretty good deal. whenever i look at a used bike i look at the chain and sprockets, also a good indicator of how the bike was maintained. if the chain is all grungey and stretched and the sprockets are all shark toothed or missing teeth it will tell the story, better then a new set of plastics+graphics would.

i picked it up.. its missing a few bolts, front wheel is missing a spoke, but there was clean oil in the case and the air filter was pretty clean. The bearings seemed pretty good.. However, he was not able to get the cylinder off but he was so certain that he said if i take the cylinder off and its scored he will give me my money back. Seemed like a good deal. Im going to clean it up good tomorrow and get to work.. Should be fun. I will most likely be posting here more in the near future :)

sweet deal man. where abouts in new york are you from? i'm from up there just moved down here to tx but im moving back in the spring.

definitely check to see if there is any sign of fork oil leaking..make sure the forks feel good..check linkage and make sure the shock isnt blown up....good luck

dmm698 said:

im about 30 minutes west of albany. As for the bike, it does only need a piston and ring. Everything else seems ok. Needs bolts, thats for sure..

When i did take the head off though, there were some moist spots on the crank. Now, there is a missing bolt on the stator cover and the clutch cover so could that be making it not seal right? I washed the bike two days before i took the cylinder off so maybe water was able to get in there and stay in there?