IF you seem to be getting more out of one side, check the plugs and see if they look the same (color wise) and do a check on the valve settings. If the cylinder isnt firing all the time, then there will be less coming out of it. Pull the plugs and get leave them on the wires, then get a GOOD ground on the plug threads (wire wrap and tied to a good frame ground) and check the spark, should be big and healthy. See if they look the same one each side. If the right one is week, try reversing the coils and see if the bad spark moves with the coil, if so the coil may be dying.