I'm trying to get a motorcycle back in service. I've cleaned the carb jets once already. The front cylinder appears to not be firing based on the amount of heat I feel in the exhaust pipe(hmmmm),compared to what's coming out the rear exhaust pipe (yeeeouch!). I switched the coils, front to back, and it ran the same way. I checked the float bowl in the front carb, and it had fuel in it. What are the next steps I should take to diagnose the problem?