here's what i've learned with my xr400. it's all related to flooding the motor...so, when i crash/get off/tip over...if i'm able i'll quickly turn the petcock off. this helps a lot. i can usually turn it off faster than i can get the bick up so it helps to limit the flow of fuel. second, if i'm lucky enough to be on a slope i'll 'bump start' instead of trying to kick it (the xr400 doesn't have THE button). if you're not in a hurry, giving it some time for the fuel to evaporate will help to.
however, the best advice i could give you is to not crash...this has several advantages...one, engine stays running; two, it doesn't hurt like crashing does; and three, bike retains that "new bike" look longer.
