Scott,
I had that problem on my 400 it ended up being the points where out of adjustment a little. Also check the carb might have a little dirt in it I've also had that happen and the problem was the same as yours.
I had that problem on my 400 it ended up being the points where out of adjustment a little. Also check the carb might have a little dirt in it I've also had that happen and the problem was the same as yours.