Possible Submerged Motor ??

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Here is my concern. I bought a used motor on which the started motor was non-operational. I bought it non-running as-is. The motor is a 1970 Merc 800 that looks in amazing (flawless) condition. Owner promises the motor runs perfectly, was meticulously taken care of and has had very limited use. I got the motor home and took the starter motor apart and found a mass of rust inside. Must have been 1/2 cup of rust and debris came out of the housing. Everything was rust covered and flaking.

My assumption is that this motor has been submerged. I have gone over the exterior of the motor in fine detail and see NO signs of rust or corrosion, not even ON the starter.

Did a compression test (see other topic) and got good results I think. Should I be concerned about the motor?

My plan now is to get the motor running and get on the water with it. If there is internal damage I'll know soon enough I guess. I don't see the point in tearing the motor apart for further inspection. If its damaged there is nothing I can do ......... is there?

Is there any other way of looking a little deeper into the motor without tearing it apart?
 

rdnk_4_lf

Petty Officer 3rd Class
Joined
Jun 10, 2008
Messages
93
Re: Possible Submerged Motor ??

well the starter could have gone bad and he replaced it with a used one that had been left outside
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: Possible Submerged Motor ??

Pull off the transfer covers on the starboard side of the motor and inspect the cylinders, pistons and rings. Look for rust, although, if the motor had good compression, I doub't you will find any.

What about the distributor? Is it rusty/dirty inside the cap?
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: Possible Submerged Motor ??

Pulled the distributor cap this evening and found everything inside clean(ish) and dry. No corrosion or other signs of water that I could see although the contacts could use some cleaning.

Would rather not pull the transfer covers if not essential. Then I'll need new gaskets. Are the transfer covers the intake side of the motor?

What else could cause so much rust inside the starter?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Possible Submerged Motor ??

Like post #2 suggested, the starter spent part of it's life in an outdoor junk pile, and got pressed back into service one day, rust and all.

Clean it up and try it out.

hope it helps
John
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: Possible Submerged Motor ??

Hoping that was the story with this starter.

No hope of rebuilding it though. Brush holders, springs, brushes are all melded together. The two main thru bolts are a mass of rust and I had to pry them out of the holes they were so enlarged with rust. Armature looks very rough as well.

Will investigate further when time permits.
 
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