76' 70 hp Starter Issue

[Ruefus]

Hi Folks,
Been browsing through everything I could find here, 'bout 4 days now.
I have used many of the great tips to get as far as I have, now I'm stumped.
I have determined that the starter is shot. It is a Prestolite, numer on case: MCD 4110 12V. It has a 10 tooth pinion. Everything I have found on the web as replacement number OMC 386657 or 586281 indicated a 9 tooth pinion. Which is correct?

It's an Evinrude.

Purcitate the hep!
Ruefus

 

[HighTrim]

Re: 76' 70 hp Starter Issue

Just to start, what has led you to believe that it is shot? They are often needlessly replaced.

If in fact she's toast, first bring it into a repair shop. They can be rebuilt for MUCH less than if you were to buy new.

 

[Ruefus]

Re: 76' 70 hp Starter Issue

Thnx for the rply. I used the voltage drop test procedures from the Clymer to test it. I even applied power directly to the starter positve post, nothing.
I pulled the motor and using 'the book' removed the commutator cover. Lots of black dust escaped along with pieces of one of the brushes. It appears the brush attached to the insulated terminal was worn completely down to the wire. I would be willing to attempt a rebuild myself except it appears the brush attached to two of the field coils would require either replacing those field coils (one of which has a small tang soldered to the inside of the case) or trim and solder the new one in place. Do you still believe it may be cheaper to have a shop rebuild it? I can definitely go for cheaper as long as it solves the problem.

 

[jtexas]

Re: 76' 70 hp Starter Issue

The prestolite motor is out of production. I found a brush set at my local evinrude parts dealer (outrageous price $50) and just cut & soldered the leads. Been working fine for a few years now.

I have a feeling that you could find cheaper brushes at a starter/alternator rebuild shop, not the same part number, but the same function.

Also, you'd be surprised what shows up on ebay every now & then.

 

[Ruefus]

Re: 76' 70 hp Starter Issue

Thnx jTexas. I was about to post additional info. I think it may make a difference. The armature has some pitting, apparently from the arcing created by the worn out brush. I am concened that this will cause new brushes to wear out more quickly. Can the surface of the armature be lightly filed or sanded to reduce or eliminate the pitting and restore a smooth surface? Or does it matter?

Ruefus

 

[Ruefus]

Re: 76' 70 hp Starter Issue

I was also thinking (very scarey) . If I do need to replace it will a 9 tooth gear work? My knowledge of gears would say no. SO, I waas wondering if I purchased a motor based of the latest part number shown for this engine, could I simply remove the 9 tooth pinion and place the 10 tooth pinion from my existing motor on it? A bit of Frankenstien for ya!

 

[jtexas]

Re: 76' 70 hp Starter Issue

ya the pitting makes a difference. the "book" should say what the tolerances are, but I'm not convinced that kind of resurfacing is really a "do-it-yourself" type thing. But I'm sure a rebuild shop guy could tell you if it can be saved.

maybe somebody else more familiar with the "tooth count" issue will chime in.

have you tried www.shop.evinrude.com click on 'electronic parts catalogue' drill down to your year/model.

 

[Ruefus]

Re: 76' 70 hp Starter Issue

OK, did some checking. The 9 tooth pinion will work just fine if purchased on a new starter motor. The diametral dimension of the gear is what changed, so the motor manufacturers simple adjusted the mounting provisions to account for the difference. IE move the motor closer to the fly wheel to maintain proper tooth ingagement.
Long story short the cost of a new armature and brushes (possibly 2 field coils) plus labor warrents the purchase of a new starter.
Thanks for the assistance.

 

[jtexas]

Re: 76' 70 hp Starter Issue

Good to know -- thanks for coming back with the answer