Recently my bike was doing something strange. It would start up just fine and run for 2-3 minutes then bog down and die and refuse to start. I thought about what could be happening and decided it must be a petcock issue. i took it apart while still attached to the tank to find a nasty looking outside diaphram. So u just reversed the side the spring was on to hold it open, put it back together. Started right up with no leaks. Nice fix, just gotta remember to turn it to off when not riding