I plan on installing an xr 400 cam, JE 10.5:1 piston, and an E-series exhaust on my 400ex. I am just wondering if I need to replace the stock clutch springs with heavier ones to avoid clutch slippage, or will the stock springs be alright to use. The bike is a 2000 model, and has not been ridden very much. If anyone has any information that may help me I would appreciate it.

Thanks

 

YOU should be fine even with a big bore kit. YOu might as well use your stock parts as long as posible.