1972 85hp Johnson

" Has anyone ever tried conver

" Has anyone ever tried converting the breakerpoint/capacitor discharge type ignition system on a '72 85hp to a breakerpoint, condensor, standard type ignition coil?(Ignition coil and system similar to that used on the OMC I/O's of the 1970s) "

Mike...It has been done may a

Mike...It has been done may a time. I actually have a motor that is still running with this conversion. Has been running fine for over 5 years. You will lose a small amount of power at top end though this is hardly noticeable.

" Those points were made to op

" Those points were made to operate at very low voltage,applying 12 vdc will burn them up very rapidly use J4J plugs "

" Thank guys. Tony, did you us

" Thank guys. Tony, did you use a ballast resistor at the pos side of the coil to reduce voltage/current? And did you run wires and attach condensors to both sets of points or use a single condensor at the neg side of the coil? Jupiter, why the J4J plugs? All help is appreciated. Anyone have a wiring diagram of the conversion? "

Mike....There is a single wir

Mike....There is a single wire that comes off the points plate. Connct this to the neg side of coil. Attach a condenser (auto type designed to run 12V) to same side of coil. There is a purple wire on your terminal board and this will supply 12V to your coil. I used an auto type coil designed to run 12V with no resistor but you can use an external resistor type coil with a ballast reistor.

" Thanks Tony that's what

" Thanks Tony that's what I did. Purple wire (12v), to one side of ballast resistor, then from other side of ballast resistor to + side of coil. (Voltage drops to 6V at coil). On - side of coil where points wire hooks up I used a condensor. The ballast resistor should prevent the coil from burning out but was concerned that installing the condensor at the coil wouldn't be enough to keep the arcing down on the points. Did you stay with the original spark plugs? Assume mine are. (Champion QL77JC4) "

Mike....yes I am still runnin

Mike....yes I am still running the original plugs being L77JC4 gapped at 0.030. The Q on yours refers to a resistor plug but are essentially the same. In 5 years my points haven t had a problem and these were not replaced when I did the conversion. Zeke s suggestion of running J4J plugs which now supercede to J6C sounds good as the johnson motors that used similar ignitions from factory ran these plugs. Only concern is these have a 3/8" reach and the others have a 1/2" reach. Regardsless my motor hasn t missed a beat since I did the conversion.

Thanks again Tony. I will sti

Thanks again Tony. I will stick with my plugs and check the gap.