Mercury starter problems

Designs for inboard or outboard power

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Will12
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Joined: Thu Jun 21, 2018 6:27 pm

Mercury starter problems

Postby Will12 » Thu Jun 21, 2018 6:33 pm

Hello all,
I have a 1978 90 hp Mercury outboard and I am experiencing issues with the starter. I have recently installed a brand new starter, but I am still experiencing problems. When the motor is cold, the motor will start just fine however, once the motor is running and you turn it off it will not start again. Starter also gets really hot, but once you let things sit for a while and get cool the motor will turn over again with no issue. Any help on diagnosing this issue would be great .

Thanks,
Will

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Bill Edmundson
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Location: Birmingham, AL, USA
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Re: Mercury starter problems

Postby Bill Edmundson » Fri Jun 22, 2018 5:34 am

Sounds like the starter is not disengaging.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

BillW
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Joined: Sun Oct 05, 2008 8:03 am
Location: Seattle, WA

Re: Mercury starter problems

Postby BillW » Fri Jun 22, 2018 7:47 am

I would suggest that you go to http://www.johnsoldmercurysite.com , tech help section.
Very knowledgeable folks on there.

When you say "it will not start again" be sure to specify if that means the starter will not crank the engine.
Or, does it mean that it will crank over, but that the engine will not start?

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Bill Edmundson
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Location: Birmingham, AL, USA
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Re: Mercury starter problems

Postby Bill Edmundson » Fri Jun 22, 2018 10:26 am

First question, probably the easiest. But, not it. When you start the engine does the key return to the on position or stay in the start position?
If it returns to on, it is probably a relay someplace that is sticking. Since, it's a new starter, I doubt it is the new starter.

Sorry! This is not one of my strong areas. I'm just looking for the easy way out!

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

PeterG
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Joined: Mon Dec 03, 2007 7:08 am
Location: Connecticut

Re: Mercury starter problems

Postby PeterG » Fri Jun 22, 2018 12:55 pm

Check your wiring against the diagram linked below, make sure your starter is wired correctly to the starter solenoid and the solenoid has the correct connections. There may also be a problem with bad insulation on the wiring as Mercury outboards typically suffer nasty insulation failures on their older outboards.
http://www.maxrules.com/oldmercs/Wiring/1966ona/50.jpg

This http://www.maxrules.com/index.php website is very handy but the john's old mercury site is the best.
Murphy's Law: Anything that can go wrong, will go wrong.
Griffin's Law: Murphy was an optimist.

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Jimbob
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Location: Sacramento, CA

Re: Mercury starter problems

Postby Jimbob » Fri Jun 22, 2018 2:26 pm

Just spoke with our ace mechanic at the dealership that is into boats.
He says it might be the starter solenoid or a problem with the ground to the starter.
Hope this helps.
Jim
Jim Neeley
Building a Barrelback in Sacramento, CA
viewtopic.php?f=15&t=28089#p172969


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