[Hondaowner321]

Ok so I just bought a 1999 400ex and it ran pretty good and then all the sudden I was riding it like locked down or somthing and I put it in the garage and it had other problems with spark and stuff so eventually I replaced all the wiring on it with a whole new wiring harness and everything and it starts really hard and I got it running last night and it ran good for about 3 minutes and it just shuts of randomly and makes a screeching/grinding noise and I already checked the timing and the clutch can anyone help me?

 

[LedFTed]

all connectors, should have dielectric grease in the fittings.. make sure ya check your grounds..
screeching/grinding, i cant help ya with. unless you are talking about nieces..

 

[Saltzuki123]

sounds like its seizing,when they cool back down sometimes the piston will unstick,its probably time for a rebuild