my brother just bought a 1990 RM 125(he owned a '98 YZ125 up until a couple years ago, and a '94 CR125 before that), he hasnt had it long and hasnt ridden it much, but the thing is a dog... its by far the slowest 125 either of us have ever ridden...
it has an fmf pipe, aftermarket aircleaner(not sure which) with the lid removed and a few tooth bigger rear sprocket...
according to the previous owner it was just recently rebuilt, it starts on the first kick everytime and after we messed with the jetting some it runs good, but something just doesnt seem right, the thing has no power to speak of... it hardly wants to even pull itself to get going, has no bottom end, has a little bit of a hit in the upper midrange, and then does nothing but make noise and vibrate on top...
it revs up alright and accelerates fairly decent once underway, but its like there is no power at all to the acceleration... just motion... and it doesnt take much sand or mud to sap what little power it has(so trail riding it is a pain)
even where it has excellent traction it wont pull the front tire off the ground in anything but first gear and even then you have to use the clutch and MAKE it do it...
I'm not firmiliar with RM's of that time period and never really dealt with them, but with all the stuff done to it I would think that it should go pretty decent...alot more than it does... where these things just naturally doggy, or is there maybe some inherent problem that they had that I should be looking at?
I dont know if any porting has been done, but we pulled the cover off and the exhaust valve actuator arm and valve seem to be working fine, we didnt dig into the actual valve yet though, thats next on the list, along with a topend rebuild(so WE know its recent)... anyone know if there were any problems with these valves that I should be looking at?
something has to be done or the bike has to be sold and something else bought...
I've ridden 80's were faster than this thing, its absolutley no fun to ride as it is...
it has an fmf pipe, aftermarket aircleaner(not sure which) with the lid removed and a few tooth bigger rear sprocket...
according to the previous owner it was just recently rebuilt, it starts on the first kick everytime and after we messed with the jetting some it runs good, but something just doesnt seem right, the thing has no power to speak of... it hardly wants to even pull itself to get going, has no bottom end, has a little bit of a hit in the upper midrange, and then does nothing but make noise and vibrate on top...
it revs up alright and accelerates fairly decent once underway, but its like there is no power at all to the acceleration... just motion... and it doesnt take much sand or mud to sap what little power it has(so trail riding it is a pain)
even where it has excellent traction it wont pull the front tire off the ground in anything but first gear and even then you have to use the clutch and MAKE it do it...
I'm not firmiliar with RM's of that time period and never really dealt with them, but with all the stuff done to it I would think that it should go pretty decent...alot more than it does... where these things just naturally doggy, or is there maybe some inherent problem that they had that I should be looking at?
I dont know if any porting has been done, but we pulled the cover off and the exhaust valve actuator arm and valve seem to be working fine, we didnt dig into the actual valve yet though, thats next on the list, along with a topend rebuild(so WE know its recent)... anyone know if there were any problems with these valves that I should be looking at?
something has to be done or the bike has to be sold and something else bought...
I've ridden 80's were faster than this thing, its absolutley no fun to ride as it is...
