" Tony.... Starting in 1973, O
" Tony.... Starting in 1973, OMC incorporated a "Magneto Capacitance Discharge" type ignition whereas the powerpack derived its voltage from a stator/charge coil setup which was situated just under the flywheel. I suspect that your engine is one that was built prior to that which used a "Battery Capacitance Discharge" type ignition, and depended on a battery for its power supply. That type ignition existed from 1968 to 1972, and yes..... those powerpacks were always quite expensive. Clean, tight connections (all connections) were/are a must. Also it was/is mandatory with that system to use a battery in tip top condition with a rating of at least 70amp hrs. Any deviation from the above and a person was risking a blown powerpack! Also, as the engine and electric starter got some age on it, the elec starter had a tendency to draw power from the pack when starting, resulting in excessive cranking, improper voltage to the pack, etc. The cure for this is to install a diode between the starter (heavy red wire)terminal and the (purple lead) power connection at the terminal block leading to the pack... making sure that the voltage travels from the starter to the pack lead, not vice versa! Summarizing... poor loose, dirty, etc connections or a cheap battery, or excessive starter voltage draw, or any combination of these WILL possibly damage that type powerpack. The above suggestions should eliminate the once a year replacement problem you've encountered. Good Luck. (Joe - 30+ years with OMC) "
