Hi, does anyone have any recommendations for a rotor problem I'm having on my 1964 60HP evinrude model number 60453S, this has the old time magneto. I routinely burn out the rotor. I have changed the points, condensor and have checked for shorts. Dealers tell me this is normal to these engines, but no recommendations. I'm going through 2-3 a summer. The price has gone up to $38 a piece, and I can't afford to replace that many year. Any suggestions or help?