I have a force engine model 120LD92B, and I have a problem, I have no spark on the 3 and 4 plugs, I repace the switch box because I belive that was the problem, but I have a new one and still the same, I check the plugs cables and they are fine, the coils have continuiti and resistance on the multimeter, so I wonder what can it be.<br /><br />Thanks<br /><br />Rosh