20 hp electric start

[rock]

I am wanting to convert a 20 hp Merc serial #3758576 to electric start. Don't know year of motor but the flywheel does have a ring gear so I assume it was available when motor was built. I do have a 25 hp Merc I can canibalize if the starters might be the same which I doubt. Anyone with knowledge or parts would be appreciated. Thanks.

Rock

[David - WI]

For what it's worth pretty much all of the Ebay listings say something like this:

"This is an electric starter removed from a 1999 15 HP Mercury outboard. This starter was in good working condition at time of removal. This starter shows normal signs of wear but is in good condition overall. This was used on a variety of Mercury/Mariner outboards ranging from 6-25 hp. Please make sure this will fit your outboard before purchasing."

https://www.ebay.com/itm/26722042935...pid=1639554920

[Jim Speros]

It's been a long time but, I think there is more to it than adding a starter. I vaguely recall it also adds charging parts. Like stator and rectifier. Does your harness have yellow red wires for solenoid? Maybe kit includes harness too.

[108]

https://www.marineengine.com/parts/m...ric-components

[108]

It's supposed to warm up here in a couple days for a bit, I know there is an old 20 with e start in the graveyard. I'll look.

[rock]

I would sure appreciate it. I knew there would be no new ones available but was hoping for a used one. Jim mentioned needing a stator and rectifier but I don't see why that would be necessary. The link you posted shows a stator and a rectifier but this motor only has a stator and unless that small box on the starboard side is a rectifier, I don't think this one has one. These old 20s are great motors and i want to replace the 25 on my jon with this 20. I am old and shoulders are shot so rope start is an issue. Thanks.


Rock

[David - WI]

Mercury rectifier $87... better rectifier $5.80.

https://surpluscenter.com/35-amp-100...dge-rectifier/

[Onetime]

Rectifier needed to convert stator ac to dc for battery.

[David - WI]

You could probaly put a 5# LiFePO4 battery on a quick disconnect in it and just charge it when you get home if you wanted to. Probably get a dozen+ starts out of a charge (it's not cranking a V-6), and you still have the recoil so you won't be paddling if you run out of juice.

Put the same disconnect plug on the battery charger. Put LED bulbs in the running lights, if you use them.

(If you don't actually have a charging system.)

[108]

Garden tractor battery will start it all day long, no need for the charging system

[rock]

That's what I was thinking. The battery is only for starting and this thing has been running without one since the 70s.

Rock

[skialot2]

If you just want electric start you can just install a starter with solenoid with a push button on the motor. No need for a key. It will still shut off the same way. You could probably start it 100 times before draining the battery. I would just use a solar battery charger to recharge the battery. But, if you want it to charge, you would have to change the stater to one with a lighting coil and add a rectifier.

Amazon.com : Callsun 12V Solar Battery Charger - 20W Waterproof Solar Trickle Charger & Battery Maintainer with IP68 Smart Controller, High-Transparency Tempered Glass, 12V Solar Panel Kit for Car/RV/Boat/Trailer : Patio, Lawn & Garden

[108]

That's what I was thinking. The battery is only for starting and this thing has been running without one since the 70s.

Rock

I use a 340 cca for rubber boat. Works fine.

[rock]

108...let me know what you find and how you want to get paid. Appreciate the effort.

Rock

[108]

Grabbed everything you should need, does your rope starter have the boss for the starter?