Had no power at full throttle found out it was #2 coil, changed it with a 1979 70 hp coil this motor is an 83,(dont know if there is a diffrence) ran great for about 5 min then went back to no power at full speed! Thinking it was bad changed it again with the another coil from the old motor, same thing 5 min then sputtering and no power! are the two coils interchangable,and also my volt meter is running at 16 volts is that high could it be an overcharge,idont know, been spending the last 2 days trying to find out! CAN SOMEONE PLEASE HELP!!!!!!THANK YOU IN ADVANCE!!!! ANY ADVICE WOULD HELP!!!