1974 mercury 1500 outboard charging system

[chrishayes]

Ok guys, I have started to tear into this motor to try to find the cause of some very poor running issues. So far I have started to look at the charging system because the motor does not charge my batteries. uhh I have none! There is no rectifier or any wiring associated with it! I took off all the cowling and got to the flywheel and found the stator sitting there with 2 frayed wires looking at me that are too short to splice...Does anyone have any info on what all I will need to get this system up again? obviously I will need the stator and rectifier, is there anything else? Anyone able to take a picture of the placement of the rectifier and wiring would sure help me out!

Would not having any of these items working cause the motor to not want to go full throttle even with the throttle pushed all the way forward? what other effects could I see from not having it?

Thanks, Chris

 

[Laddies]

Re: 1974 mercury 1500 outboard charging system

Basicly that and a short wire to connect the system to the solinoid. Here's a wiring diagram.

 

[OldMercsRule]

Re: 1974 mercury 1500 outboard charging system

I would start real basic and pick up a manual fer the engine and verify cornpression, then pull the cap and inspect the cap and rotor and center carbon piece, (rotor doesn't come off).

Plug wires screw into the cap, inspect spark plugs, (change if problems).

Change your fuel pump and make sure you have solid 3/8" fuel lines from the male fitting to the top carb, (no leaks).

Inspect the rest of yer wirin' harness to make sure it is sound.

Rebuild carbs (totally if ya touch em at all), if necessary.

Once it runs properly then deal with the stator rectifier issue, (make sure the battery remains fully charged while running it take a spare real strong battery with you on yer sea trial).

Me over priced $.02 JR

 

[chrishayes]

Re: 1974 mercury 1500 outboard charging system

thank you for the diagram! what a help! Also, I agree that I will not buy these parts until I do a compression test tonight. If I remove the distributor cap and rotor what should I look for or test for? The plug wires are original(dear god) and have a lot of dry rotting iinsulation but not exposed wire. Do you know the resistance that I should see on these?

 

[OldMercsRule]

Re: 1974 mercury 1500 outboard charging system

thank you for the diagram! what a help! Also, I agree that I will not buy these parts until I do a compression test tonight. If I remove the distributor cap and rotor what should I look for or test for? The plug wires are original(dear god) and have a lot of dry rotting iinsulation but not exposed wire. Do you know the resistance that I should see on these?

DO NOT TAKE OUT THE ROTOR!

If the cap and rotor and carbon piece looks good after you wipe them off fine if not replace the cap.

Look here on iboats fer a new internal wirin' harness and buy it (if the cornpression is good). Most of my engines have origional plug wires. Replace them if they look bad or watch it run at night, (on the muffs), if light show new plug wires!

The manuel will walk you through step by step. JR

 

[chrishayes]

Re: 1974 mercury 1500 outboard charging system

Yes, I have a manual and have been following it. Its a Clymer that covers a broad scope so it is a bit vauge, thats why I dont know where these parts go. Also, I know not to remove rotor, I appologize if I wrote that wrong...so I assume that the rotor and cap will look similar inside to a automotive type? just check the terminals that the rotor contacts on the bottom of the plug sockets and the strip on the rotor itself?

So the plug wires are not a replacement type of thing? I could harley beleive that they were orignal! Like I say they are not bad just dryroted with some light cracking. I guess I will liquid electrical tape them...

I am fortunate that the internal wiring harness is only a few years old it looks like. The PO must have replaced it. Thank god, that thing aint cheap! Is there anything that I need to pay attention to when removing the cap? dont want to make any "accidental" timing adjust ments yet due to the fact that the motor does run, just not well. Then I will link and synch once I check compression and verify that it is worth it. Lets hope.

 

[OldMercsRule]

Re: 1974 mercury 1500 outboard charging system

Yes, I have a manual and have been following it. Its a Clymer that covers a broad scope so it is a bit vauge, thats why I dont know where these parts go. Also, I know not to remove rotor, I appologize if I wrote that wrong...so I assume that the rotor and cap will look similar inside to a automotive type?

10-4

just check the terminals that the rotor contacts on the bottom of the plug sockets and the strip on the rotor itself?

10-4, and for cracks dirt, carbon contact in the center, et al.

So the plug wires are not a replacement type of thing?

"If they look bad" change 'em out. With solid copper core wires with screw in ends to the distributor cap, (that I would be tempted to change as well if you redo the plug wires).

I could harley beleive that they were orignal! Like I say they are not bad just dryroted with some light cracking. I guess I will liquid electrical tape them...

If cracked I would change 'em. Many of my old Merc inline6 engines have origional plug wires but it I see any cracks: off they go.

I am fortunate that the internal wiring harness is only a few years old it looks like. The PO must have replaced it. Thank god, that thing aint cheap! Is there anything that I need to pay attention to when removing the cap? dont want to make any "accidental" timing adjust ments yet due to the fact that the motor does run, just not well.

Nope: just use care.

Then I will link and synch once I check compression and verify that it is worth it. Lets hope.

10-4. JR

 

[chrishayes]

Re: 1974 mercury 1500 outboard charging system

10-4. JR

You say that in parenthesis ( I would be likely to change that out as well) are you referring to the cap?

I did the comp test last night and the results were posted in a new thread but I will repeat here.

#1 90psi
#2-6 ~120psi

spark plugs are not what the manual says to use. they are champion 77 instead of 76 and they all seem worn differently but they all have a light oily appearance except for the one on #1 it is dry and looks to have a whitish hard sanding color. almost looks like the same corrosion that is around the pee hole(cant be good). When I sprayed fogging oil into the cyl's some of it leaked out the exhaust hole in the foot(LU is off) any words of wisdom here?