I have the jet kit in my ex and it is still won't hardly start. My buddy has a bone stock brand new ex and it won't start. Exact same problem( gas fouls the plug). Once we burn it off and clean it up it starts right up. If the stock jet gas fouls the plug how can putting a larger jet in help? Plus the choke set-up on an ex's carb is at full chocke it gives 50% gas and 50% air. It should not matter what size jet you use. I have tried to start mine every way imagineable(by the book, no choke, etc..) I spoke with a local atv acc. shop owner today and he said that the valve adjustment is where the problem stems from. He said to change it to the high(loose) end of the range of honda's guidelines. Does anyone know what this is? He also said that this problem was not in all 400ex's. I disagreed. Everyone I know or read about on here has this problem. He also said that a properly adjusted motor should fire up in the cold no matter what size jet is in it. I figure I would try the vavles b/c nothing else has worked. Any comments or suggestions would be great. CJ
