Ground Wire.......
 

My ole flying BAS was having a problem starting his engine yesterday..it's a FPE 2.4..so I let him use my ignition from my FPE 2.4 ( I have 2 of these babies), and it startred on the first flip...Any way he put his ignition back on and he noticed that the ground wire that is attached to the engine bolt, was dirty.had some locktite on it..he cleaned it up and try again, and the engine fired up on the first flip of the prop..Moral of story....Make sure your GROUND wire is clean and attached solid to the engine bolts...........Could save you a day of frustration