i have a 2000 rm 125 and i did a top end, needs a new clutch that i'm going to be installing soon, but anyways i decided to start it up this weekend because it was a little warm so i ran it down my driveway a few times, well after it was warmed up i decided to open it up and it would bog down, so i opened it up slower and would rev right up, I then put it in neutral and i can open the throttle quickly and it revs up with no problem, only when its in gear it does this. i'm going to try cleaning the filter, anything else it could be? i don't get much smoke out the exhaust so i would think the head gasket is ok.
