won't start

[black400ex]

I have a 400ex that won't start. I had a WB rev box and being that it is about 22 degrees I thought that might be the problem. I switched it with the stock and still nothing. I have great spark and was running fine 2 days ago. I have a full tank and even took the carb and fuel lines to check for blockages. The starter is good and the battery is fully charged. Any suggestions?

[PIMP]

did you check the fuse??? maybe its a bad fuse

[black400ex]

yes, the fuse is good.

[Aceman]

Maybe you need to bump your pilot jet up a size or two. Have you tried compression starting it?

[black400ex]

The previous owner put in a jet kit, but not sure what sizes. It may be too big because if I rev it up pretty far I see smoke and its not oil. It started fine until now even if it was this cold or colder even without the choke as long as I pumped the gas a few times.

[black400ex]

Is compression starting the same as drift? Rolling it down a hill and popping the clutch? If so, yes, I have tried this numerous times. Thanks.

[raptorrider686]

Where you riding on the trails and it started to spit and sprutter on you? The it s turned off completly? Then it wouldnt start again?
If that is the case i know the problem.

[Rico]

Your plug is fouled that's why it won't run.

put a new one in there and throw that POS WB CDI in the trash.