Take the tank off. The two ignition coil connections for each side of the engine correspond to that side, but not the order. Connect the left most coil connection with the plug on the inside. Same convention with the other side of the engine. SO, if you were to arbitrary number from left to right the coil connection and the plugs it would be: 1 with 2, 2 with 1, 3 with 4 and 4 with 3