It is my understanding that the 04 440 sno pro had a hot start feature integrated into the electronic ignition, which retards the timing significantly to heat the exhaust pipe just before takeoff. I have a 04 and cannot seem to figure out where this button is supposed to be or is at. I bought a 2004 Service manual and of course it has nothing in it about the 440. The sled will start fine but then a few seconds after running it starts missing really bad and opening the throttle causes backfiring. If the engine has not been run for a long time it will idle normally for a minute or two then start running like crap. If its still warm it will start running like crap withing 5 seconds of start up. I have called all over trying to get some wiring diagrams or some information on how this hot start feature operates. I think the ignition module is in this hot start mode but am not 100% sure.