I have an 07 wr450F that has been bullet proof for the last 3 years (got it in 08). I had an issue when I was on the mountain in Hatfield last winter where the bike would just die. then would not refire for around a minute. It did this several times before the end of the trip. I could not replicate the problem when I got it home and it was fine this spring at hatfield. It was also fine this summer when I actually got out to ride it a couple of times. Today it started happening again. It was very difficult to start (the bike would always start with 4 pumps of the throttle before no matter what) Then ran it a bit to warm it up. It then died and would not restart for 3 or 4 minutes. When it finally got running again it did the same thing. We drained the fuel and drained the fuel in the float bowl and refilled it with fresh fuel. Still did not want to start, and when it did it ran till we let it idle and then died and would not restart. Never had a single problem with the bike before this happened. Ran like a top after uncorking and rejetting it to no longer be lean as it came from the factory. HELP!!!!