learn something new every day, there is a hot start on an 06 440. thought that was just for the 450 4stroke engines. At least on the 4 strokes it shoots a bit of gas into the cylinder to aid in starting. I am not sure how it would work on a sled carb though. so if unplugged it would not shoot gas in and probably become harder to start. just one way to look at it. I am interested now and subscribed. steve
It's the preheat button, it is not to aid starting. when the button is plugged in, the mpem is in race timing curve, when you push and hold the button with the engine running, it changes the timing to preheat the pipe to help on the holeshot for snowcross racing. You will start building heat rapidly in the pipe and is hard on your reeds if you start reving the engine too high I believe no higher than 5000 rpm. timing returns to normal race curve when you release the button.
If you unplug the preheat button connector from the harness, the mpem will change the timing curve to trail mode. This is when you do the trail conversion to run pump 91 octane. (low comp domes, trail needles, rejet/hardjet the carbs, slight clutch adjustments) maybe some other things, but I can't remember right now.
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