Hey all

My bike has a 97 XR400 engine in a 97 CR250 chassis with E-start parts off of a 400EX, the wiring harnes has parts from the XR and parts from a EX, the engine was put together by my brother Don a motorcycle and ATV mechanic for 17 years.

If it's below 50 degrees it is imposible to start my bike without putting a salamander heater on it for a while until the engine is warm.

My question is; How mant poeple have trouble starting there 400EX's when it's cold that have the White Bros. rev box?

Don had a 400EX harescramble racer tell him last week that the rev box might be some of our problem with cold starting.

My buddie that was considering the 650L engine swap went with a 440 kit instead.

Thanks Kevin

 

We've been having the same problem with our 440EX's. The stockers aren't as bad but some have more trouble than others. I just clip on the stock box to get it warm then change,no problem starting. A simple pull start also works but is a little tougher on a bike.

 

All I do is put the choke on full and open the throttle full. Tried this at -25 and my 400EX started right up first try. It really surprised me because after blipping the throttle about 3 times and turning the choke back off it sat there and idled! I've tryed choke full, blipping throttle before without having to sit there for 20mins it would not run. This always works now no matter the temp. They run so lean from the factory that this is really the best and only way. I have seen me take it into my relatives building and heat it up even because it would not start but this was before i tried this. Works great for me. Always try it without the choke first as it may not need it if the temp isn't that cold. Throttle full seems to work great for me but may be different for you. Try it.