Help!! 300ex not running!

Hi all,

I'm having a problem with my '98 300ex. It starts and runs fine for about 5 - 10 minutes and then shuts off. When it shuts down it starts to lose throttle response and then completely quits (kind of like it's running out of fuel). It won't start again until it has cooled a bit, and then it repeats the problem.

I bought it used and have ridden it 6 - 8 times with no problems at all. I haven't done anything to it since I've had it. The only thing different I can think of is my friend flipped it off a small lip the last time it was running fine, and it landed upside down (from about 2 feet off the ground). The only thing that seemed to be wrong was the handle bars were bent. After the incident we didn't ride it for very long and packed it up and went home.

Mods I know of:
Cobra exhaust and header
K&N
and I presume a jet kit

When I was having the problem I tried running it on full and half choke but it didn't make a difference. I also pulled the tank to make sure fuel was flowing out of the petcock (it was).

At this point I don't know where to start trouble shooting. Anybody have ideas??

Thanks!

-Ken

[Leo]

run it until it quits and then check and see if it has spark..

also after it quits, crack the drain screw on the carb float bowl and make sure fuel runs out..

it's possible that it could have an electrical component that goes inop when it gets hot..

Try to keep it simple and remember the basics, you need fuel, air, spark and compression to make a motor run.

Leo

[dirtclog]

when it flipped over and bent the bars down did it pinch the gas tank breather hose...if it is clogged or pinched it will cause you to quit.

[DEAL]

I had this problem with my 300ex .. it turned out to be my wiring had been worn through in one spot .. I noticed the EXACT same thing that happend to you with mine.
Take the covering off the wires down below the gas tank and look over each one of them carefully and you will hopfully find one that is broken or worn through, and if you don't its probably the black box.