You can use a light to make sure your timing is on but im am not sure if that is the problem. What you do is connect your inductive or in line cable to the MAG side plug and get a seperate 12 volt battery to connect the timing light power. The window is on the top of the recoil cover. The mark on the block where you lined up your timing is the same as the arrow on the recoil cover. That way if you have to adjust it you dont have to take off the recoil cover. Hope this helps.