1971 johnson 60hp coil retro-fit

[lastout]

hey guys, i have been reading that i can retro-fit my 60hp johnson with an old automotive coil, ballast resistor and condenser to get rid of the original coil and amplifier (because they cost so much). does anyone know the specifics of this and which parts i should buy? i'm no mechanic so please go slow. thanks!

 

[Dogger CDN]

Re: 1971 johnson 60hp coil retro-fit

Hi lastout.<br />I have the same engine with spark problems and am maybe going to try the same thing.<br />You won't need a ballast resistor if you use an automotive coil that is meant to run without a ballast. They have they're own built-in resistor, so wiring will be easier.<br />To rig up this system you will run a wire which has 12V when the key is in the start and crank positions, but is dead in the off position to the terminal marked + on your new ignition coil. The terminal marked - connects to the white\ black stripe wire from your points under the flywheel. You must also connect an automotive ignition condensor to the - terminal. I'm thinking that the condensor off a late 60's GM engine should work.<br />After hooking up coil, take the coil wire from your original coil, and plug it into the center tower of new coil.<br />This system should work. If it won't I'm sure someone on here will tell you.<br />Godd luck

 

[lastout]

Re: 1971 johnson 60hp coil retro-fit

i appreciate the info, but can anyone recommend a specific coil (or does it even matter?) for me to use. your wiring info was great and i will try it a.s.a.p.

 

[Dogger CDN]

Re: 1971 johnson 60hp coil retro-fit

Hi again.<br />Any automotive parts store that is worthwhile will be able to tell you which 12V coil can be used without a ballast resistor. Most automotive parts stores sell universal 12V coils both ways for use on tractors, hotrods, or construction equipment. They are the size of a regular car ignition coil so they're not that large, and will fit almost anywhere.<br />UAP/NAPA also sells a universal high-performance ignition coil that will work, and is a little smaller.

 

[Yepblaze]

Re: 1971 johnson 60hp coil retro-fit

One for a 69 Mustang. Any model motor from your local auto zone or napa auto parts should work as they are 12 volt internal resistor type.

 

[lastout]

Re: 1971 johnson 60hp coil retro-fit

thank you all very much! i will try this this week. i'll try to leave a note later to say how it went. thanks again!

 

[Dogger CDN]

Re: 1971 johnson 60hp coil retro-fit

Hi lastout.<br />Tried it tday with the coil and condensor off of a Kohler K341 lawn tractor single cylinder engine. Worked great. Fired right up, and ran smooth. Kohler coil is slightly smaller than car coil so it fits into spot for old amplifier and coil great. It didn't hurt that I had these parts lying around either.<br />If anybody can see any reason this won't be a long term repair, it sure works great so far. Even sprayed motor down with hose while running with cover off, and it never missed a beat.

 

[Walker]

Re: 1971 johnson 60hp coil retro-fit

I don't think your stator(alternator) will keep up with the draw from the ignition system but that shouldn't be a problem with good batteries and daily re-charge.

 

[Dogger CDN]

Re: 1971 johnson 60hp coil retro-fit

What does the stator provide for a charge amperage on this motor? I read somewhere that it was 12 amp. I tested the draw on this coil system while running, and it showed a draw of 4-5 amps.<br /> My battery is a 750CCA, 220 amp/hour group 27, and my only accessories are running lights. I'm thinking that if I cranked the motor 5 seconds at 100 amp, and used 7 amp for ignition and lights, that it would only take 100 seconds to bring battery back up to charge with the 5 amp extra charge rate, then after that the battery would stay fully charged with 5 amp to spare.<br />Would somebody please let me know if my thinking is out-to-lunch