YZ 125 Help

[MX851]

So heresthe story, about a month ago I was riding then all of a sudden the clutch starts slipping like crazy and sometimes I couldnt pull the clutch lever in. After messing around with at the track as much as possiable i decide to pack it up for the day. After washing the bike down, draining the fluids, and removing the clutch cover I found on of the OEM friction plates had broken up in the clutch basket :bang: so I tear down the motor and replace and damged parts and bearings. So once I get it back together I take it out for a ride at the local track, it ran fine for about 45 minutes of ride time and then it happened again, slpiping clutch, clutch lever can't be pulled in, and now this time I get a boug from the engine that wasnt there before. So I take it home and wash it, drain the fluids, and pull the clutch basket. This time no broken plates or other broken clutch components. The oil I drained out was black and burnt and looked like a little bit of coolant was leaked in. I pressured tested the radiator and that was ok. Anybody got a idea?

Thanks

 

[blueflash]

Maybe a coolant leak after the engine has warmed?

 

[Blue 250]

Was the oil milky or grey? That could mean a bad water pump seal. Also what about your clutch lever freeplay? What kind of tranny oil do you run??

 

[Blue 250]

Also was your baskit or clutch boss grooved?? That might cause your clutch to slip. Are your clutch plates discolored??