Converting From 6V To 12V Starter

[mercuryspecialist]

I am trying to better understand what can be done to replace a 6 volt electric starter motor on a 1956 Johnson FDE-10 with a new 12 volt starter. It seems that the spacing of the starter motor through bolts is slightly further apart between the original 6 volt starter motor and a new 12 volt starter, so can one (reasonably) successfully mount a new (12 volt ) starter to the original bracket, or is a 1957 (FDE-11) bracket the solution, or possibly another approach? If a 1957 bracket is the "ticket", can these be reasonably found? Must a (1957) Johnson bracket be utilized, since the part number differs from a 1957 Evinrude bracket? Are there any issues with the (12 volt) starter motor (to replace a 1957 starter) mating with the (1956) flywheel?

Thank You In Advance,
Joe

[frankr]

1957 bracket is the way to go. However I wouldn’t expect it to be real easy to find. And the Johnson bracket is different than the Evinrude bracket because of the shroud mount. Also different than the Gale bracket, in case you are wondering. Also different than the later ones with fiberglass hoods. If you have a 6V starter and Johnson bracket, I suggest you use it and run it on 12V. It should start so instantly that there isn’t much danger of overheating it.

[chris-p]

Yeah, I was going to ask…..why do you want to change the starter? The starter will handle 12 volts. Just don’t crank it endlessly.

The easiest thing to do would be to wire in a resistor, to protect all components.

[mercuryspecialist]

Hi Frank and Chris,

Thank You very much for the replies. I was trying to help a customer, and my knowledge of OMC products is short in this case. I am told that the original 6 volt starter is toast (according to a starter shop). I was smart enough to understand that the 1959 and later bracket likely would not be a good solution, but I did not know about the variations on the 1957-1958 OMC models (again appreciated to learn).

Best Regards,
Joe

[outbdnut2]

Like others said, I’d keep the 6 volt starter – it will work fine n 12 – same thing is done in old car conversions. I’d get a 12 volt starter solenoid like Sierra #18-5807, available at discount online boat places. The choke actuator solenoid should have a resistor added in series with it that is the same resistance as the choke coil to soak up half the voltage – use one with a 5 watt rating.
Dave

[crosbyman]

the resistor can drop voltage ok but it must also pass enough current to allow the starter to be strong enough to do its job

the higher the wattage the better

Joining AOMCI has priviledges 🙂

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