OK, so For a long time ive been trying to fix the issue of my 450 stalling when its hot, the throttle response goes to hell, and it likes stalling while idling and coming out of idle, when hot, always have to be on the gas to keep it running. When it is stone cold, I can slam the throttle wide open idle it until its hot, runs how it should while its warm. I've checked valve clearances, and rebuilt the carb, only thing I can think of is the coil or CDI now, even took it to a mechanics and he couldn't fix the problem... just made it a bit better. My friend has a 03yz250f - would I be able to take the coil off of his bike and try it on my wr450, just till it gets hot and see if it stalls out. If that doesn't fix it, would I be able to swap the CDI?