I have a 1994 suzuki dt 40 that I have rebuilt the carbs on that now runs better than it did. I broke down twice when I wasn't out that long and it just died. I couldn't start it back up. Fuel pump is good and new gas in clean tank with Seafoam and Startron in it. When running with the muffs it starts fine but runs rough and has a miss that can almost be a backfire. The water pump is new and is pumping and it seems to be pumping oil. Any help out there?