K I washed my quad and let it dry for a while. I didn't wash the engine very much just mostly the plastic. Then I let it air dry, and when I came back I tryed to start it but it wouldn't go so I put on the choke and it started so I turned the choke off but then it stalled. I tryed it again but with the choke off and it flashed right up but there was a "PUH!" sound from just under the front of the seat and the plastic pushed out on my legs. Felt like a mini explosion... but I don't know what it was. I runs fine now but any thoughts to what it was?

 

You may have gotten water in your pipe. It's possible and could make a similar sound.