Adding electric starter on a 25hp Johnson...

Millertimefl

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Sep 27, 2009
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6
I have a 76 25hp Johnson (25R76E) and it has mounting for an electric starter and I want to know what is involved in adding it. I don't see any wiring or start buttons.
Questions:
Can I just buy a starter and mount it and add my own switch?
Will just connecting it to a marine battery be enough to turn the motor over? Do I need a solenoid?

1 more question: What is the difference in the model # 25R76E & 25E76E?
Thanks!
 

bktheking

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Jul 29, 2008
Messages
5,057
Re: Adding electric starter on a 25hp Johnson...

You'll need a starter and solenoid for certain as well as wiring from the battery and too and from the solenoid and some way to activate the solenoid. You could buy a simple marine keyswitch and just build a box housing a fuse, solenoid and keyswitch.
 

Millertimefl

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Sep 27, 2009
Messages
6
Re: Adding electric starter on a 25hp Johnson...

What exactly does the solenoid do other than act as a switch? I thought a standard key switch would maybe work...
 

bktheking

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Re: Adding electric starter on a 25hp Johnson...

That's all a solenoid does, puts power to the starter when activated. You could get creative and use the marine keyswitch to shut the motor off when moved to the off position or possibly wire up a priming system or accessories, the possibilities are endless :)
 

tashasdaddy

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Re: Adding electric starter on a 25hp Johnson...

the key switch wiil not carry enough power to the starter, the solenoid is a high amperage switch, activated by low amps.
 

bktheking

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Re: Adding electric starter on a 25hp Johnson...

Just a key switch alone (wires too) would get fried due to the high current requirements of a starter / Amps a battery would put out, TD is right, that's why I said you need a solenoid, it's not a choice.
 

emdsapmgr

Supreme Mariner
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Dec 9, 2005
Messages
11,551
Re: Adding electric starter on a 25hp Johnson...

OMC probably made an electric starting kit for that engine. Looks like they have discontinued it. The only one they still may offer is 173964, which was a kit for the 20-35 hp engines from 1977-1987. The kit had things like the starter, solenoid, wiring, key switch. It did not include any charging system and did not require the flywheel to be changed out, as yours must already have teeth on it for the pinion gear. This later kit sold for over $400. You could probably buy a complete used 1976 25 hp electric start engine for a lot less than that and transfer the parts to your engine.
 
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