I seem to have a little problem with my '05 450R, while pushing the throttle hard it will sometimes cough or tries to die if I don't let go of it. I first experienced this problem while running it cold, I've been suggested that I should let it warm up a few minutes before pushing it, but this weekend it did it again after a couple of hours of riding. It only did it a couple of times and then it went back to normal. What could be causing this? The engine is completely stock.

 

Without being able to hear what it is doing it is hard to say.

Since it happens at high throttle, I'd suspect a fuel restriction (dirty screen, some garbage in the float bowl).

 

It doesnīt sound wierd, and itīs not constant, it just tries to die, and itīs only for a couple of seconds, Iīll let go of the throttle and push again and it will be ok...

 

I'd say check out the fuel screen, and the carb.

 

It could be something like that but with my 450r i always let it run for maybe 2 minutes before giving it a lot of gas and then putts around a bit then drive it hard and see what happens. because the same thing can happen to mine if reved out right away.