3 cyl 65hp Merc - teach me a few things...

WCTori

Seaman
Joined
Feb 21, 2015
Messages
53
I always set full throttle timing two degrees less than spec on those. It has to do with the gas. It loses octane over time in boats that aren't used frequently, and that's what fries #1. Retarding wide-open-throttle timing by two degrees prevents that with no discernable loss of top speed.

Thanks for the tip Willy, I may hit you up for help setting the timing when i start reassembling things..... Got a Suzki DT60 on my plate first.
 

WCTori

Seaman
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Feb 21, 2015
Messages
53
That will be in a new & other post lol

Nah, I assume that was a bit of a slam, but it's cool,.... you don't know me. I build the Suzuki motors all the time. They're much simpler than this Merc motor. At least at this point for me.....

Anyway, i got the pistons cleaned up tonite along with their rings and lands. The rings were badly stuck with sticky 2 stroke residue. All like new now and the crank is in. Thanks for the help getting this far.
 

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The Force power

Commander
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Anyway, i got the pistons cleaned up tonite along with their rings and lands. The rings were badly stuck with sticky 2 stroke residue. All like new now and the crank is in. Thanks for the help getting this far.

Nice job!!! did you have to swap Pistons? or just Clean/hone the walls? Tell us your event.

I Cleaned the seals & applied some engine (red) silicone (between the 2 half) under the the seals also the shrink a little

Clean-up the crank end with emerald-cloth if still bad... install the seal(s) slightly off-set


and no "slam" intended by any means. meant by it; being a new bowl of wax
 
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WCTori

Seaman
Joined
Feb 21, 2015
Messages
53
Nice job!!! did you have to swap Pistons? or just Clean/hone the walls? Tell us your event.

No swapping, just removed the rings and cleaned back to "like new" There doesn't appear to be anything wrong with this engine other than it sat for a VERY long time. Motor was actually froze from the gooey 2 stroke sticking the pistons to the walls. I actually had to beat the case half away from the crank.

Onto my next question,......

Where can i get new seals/gaskets for this motor ? I assume these cork seals should be replaced,.... but i dunno, maybe they are reusable.
I don't know the year of the engine, only that it's before 1976
 

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WCTori

Seaman
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about your question........I gave my opinion & raceone gave his. hopefully more will pipe up.

You lost me.... (if you were talking to me) I don't see a response to my question about where to get gaskets/seals.
The only thing i see from Raceone is a comment about red silicone. I'm not using red silicone ???
 

The Force power

Commander
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that's because this started already before you asked the question;
see posts #25 thru #27

I applied a small amount of engine silicone on both sides of the cork-seals, just before sealing up two half
(the cork shrinks a little)

racerone disagreed with that
 

MPrimeaux

Petty Officer 1st Class
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May 10, 2019
Messages
240
I have no input on scattering your engine, but I do have some input on your wiring issues that were mentioned earlier. I have a '63 Merc and the wiring was completely shot on it also. The after market harnesses are fairly pricey for mine..... like over $200. I was able to cut into the molded plugs with a razor knife (VERY CAREFULLY!!!) and get to good wire. Cut it off and soldered on new wire to complete my harnesses. Had to do this for the internal harness and the remote harness, but it worked and only cost me for some wire and some heat shrink. Might be an option.
 

WCTori

Seaman
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Feb 21, 2015
Messages
53
Okay guys, thank you for clearing this up. I wish i had more time to stick with this, but the holidays, and new wifey are eating into my shop time.
Back at it now that i have a direction.

Cheers !
 

WCTori

Seaman
Joined
Feb 21, 2015
Messages
53
A month and a half later....... Laying hands on engine again..... Used Yamabond on the case halves, ..... looking for torque spec. Anyone have that on tip o' the brain ?

Now to assemble the electronics and start trying to salvage this wiring.

Think this cracked coil is toast ? I can seal it back with silicone.
 

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WCTori

Seaman
Joined
Feb 21, 2015
Messages
53
I always set the full throttle timing two degrees less than spec on those. It has to do with the gas, mostly. Once it starts to lose octane over time, that's when #1 seems to fry. Retarding wide-open-throttle timing by two degrees can save your motor with no discernable loss of top-end speed.

Willy, can you coach me on setting the timing ?
 

WCTori

Seaman
Joined
Feb 21, 2015
Messages
53
Was able to solder one wire, but had to make a crimp connection at the other for these two wires. They were so brittle, just touching them and they would crumble into fairy dust. Hopefully i can secure them so they don't degrade further.
 

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jimmbo

Supreme Mariner
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May 24, 2004
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12,961
For Decades Mercury utilized Wire with a Insulator that can's stand the test of time. They probably bought enough of that wire to reach the Moon and back several times. You might have to buy a new Stator. You will probably have to rewire the Entire Engine and the Wires in and to the Control Box
 

The Force power

Commander
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Feb 3, 2019
Messages
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For your sake & sanity; Re-wire the entire engine-wiring Bad/corroded wiring will lead to miss diagnosing a lot of issues.
Take short-cuts in your wiring & it will bite you in the...later.
As jimmbo said also check & repair as much wiring in the control-box as well.
 
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