2stroke_coldsmoke said:
i got a 01 rm 125 and imma put a new top end in in this winter and i was wonderin wat u all gotta replace..piston,seals,gaskets, is there anything else??
First you need to purchase a service manual for your bike.
It will detail not only all of the parts you need to replace, but it will also give you some handy tips for doing the job, plus it will give you the specs you will need to make sure you aren't wasting time and money.
For example, are you 100% sure that your cylinder is within spec?
If you don't know the exact measurements and how to perform those measurements, I doubt you are.