1955 Johnson 25 HP starter problem

fimbulvetr

Cadet
Joined
Jun 12, 2007
Messages
8
Hi. I have a 1955 Johnson 25 HP electric start, and the starter is dead. It turned the engine over a few times for my dad, then stopped working. It won't turn even with a good battery directly connected to the starter. I've pulled the starter from the engine, and am trying to figure out what is wrong with it now. It was full of copper dust from the wear of the copper brushes and gunk, so I've cleaned all that out. The copper brushes look fine and have a lot of life in them, but the insulators between the commutator segments is flush with the segments. Does anyone have any tips on testing the commutator? From what I have seen, there should be continuity between all the commutator segments, but not the central shaft. My dad disagrees, and says there should only be continuity between commutator pairs, not all segments. Any other advice on reconditioning a starter? How does one test the windings?

Thanks.
 

fireman57

Captain
Joined
Aug 24, 2004
Messages
3,811
Re: 1955 Johnson 25 HP starter problem

Welcome to iboats. Around here there are a couple of shops that will rebuild them while you wait for 30.00. Doesn't matter to them if it is marine grade or not.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1955 Johnson 25 HP starter problem

any auto starter/alternator shop can test and rebuild. if rebuildable. if not be ready for a $180 new one.
 

fimbulvetr

Cadet
Joined
Jun 12, 2007
Messages
8
Re: 1955 Johnson 25 HP starter problem

Thanks for the advice, but I was hoping for some info on how to test it myself. I like knowing how these things work :)

At any rate, I found a working used one for $40, so I figure that is the easiest way to go.

Another quick question, this time on spark plugs . . . the ones that were in the engine were not the right ones -- J11Js or something like that (it belonged to my great-uncle, he liked to mess around with it to try to get extra performance out of it, so ran it with hotter than standard plugs). Mastertech says to use J4C's, and on this forum I've read advice to use J6C's in it. I've got a new pair of each in my workshop. Which is the better choice?
 
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