1969ish 40 HP Johnson Supersea Horse

[The Starcraft Enterprise]

I have a couple questions. Is it easy to put an electric start on this engine?

Is it possible to keep a battery charged using the magneto?

 

[the machinist]

Re: 1969ish 40 HP Johnson Supersea Horse

No, it is not an easy chore, nor is it cheap because of it being that old unless you find a donor motor.

I did it on a 1970 40 hp. To do it right you need a generator that is run by a belt. I can not remember if I had to also change the flywheel as I swapped parts of a 69 35 hp. Then a regulator similar to an automotive one of the same vintage has to be used. If you can find a original regulator on this motor it may not be functinial by now. I did find a cross referenced transistorized regulator by taking the original to a old time tractor repair & he tracked down the a transistorized one by going off the output, but it was $75 7 years ago.

Also there is not enough room under the cowling so the regulator may have to be placed on the transom.

I do not believe you can capture 12 volt on this motors magneto.

 

[kfa4303]

Re: 1969ish 40 HP Johnson Supersea Horse

sucks that it's suck a chore to add the starter. I bet pull starting a Big Twin, 40 hp must be fun. I have a '60s, 20 hp pull start and it's no walk in the park :/

 

[F_R]

Re: 1969ish 40 HP Johnson Supersea Horse

I have a couple questions. Is it easy to put an electric start on this engine?

Is it possible to keep a battery charged using the magneto?

I see two questons here.

The answer to the first is yes it is fairly easy to add a starter. Not too expensive if you find used parts at a reasonable price.

The answer to the second is No, you cannot charge the battery from the magneto. A belt driven DC generator kit was an optional accessory if you feel you need one. Most people don't.

 

[The Starcraft Enterprise]

Re: 1969ish 40 HP Johnson Supersea Horse

What do you suggest? If want to put a radio in and an electric start how do I charge the battery? Should I pick up a battery charger?

 

[F_R]

Re: 1969ish 40 HP Johnson Supersea Horse

The motor only uses the battery for starting, so a charge will go for quite a while. And in worst case, you can hand start it. Anything else such as lights, radio, bilge pump, whatever, will depend on the amperage used and time. If that radio is a boom buster and you keep the dead alive with it, it may take some juice to do it. Otherwise, I don't think you will have any trouble over a weekend. Get a charger to recharge it when you get home.

 

[Dakota Dave]

Re: 1969ish 40 HP Johnson Supersea Horse

A good battery will start the engine many times and run a radio for many hours just charge the battery when you get home and it'll be ready for the next time. our old johnson never had a generator and it would start for many days without recharging. If you every run out of power you can always pull the cord. My 43.5 HP Scott starts with one pull of the cord and even my wife can start it.