early 70s Mercury 500 50hp ignition question

[wbay]

I have a 50 hp Mercury with a bad coil. I do not have the exact year for the ignition. The engine had the power head replaced when my dad bought the boat/engine in 1985. The serial number on the mounting bracket shows 5336558 which is 1979 but the ignition is an ignition driver set up and the actual ignition parts on the engine are from earlier 1970s models. The existing coil is a large red coil that fits in a mounting bracket that connects to the switch box. Coil is 332-2983. A new coil is NLA and only available used on ebay.
Has anyone run into replacing the coil on this type of ignition? If so is it possible to go to another type of coil that is still be manufactured? It looks like the CDI part 184-0001 will also attach to the switch box rather than one coil each to the spark plug as in the later models.
Any help would be appreciated.

 

[1960 Starflite]

Now that's confusing. The picture of the (switch box) sure looks like the very old magneto ignition. It has an internal pickup coil and point system. No electrical power is supplied to that system. The only electrical post on that system, simply grounds the system to shut it off. There should also be a wire coming from the tilt mercury switch that shuts the engine down when the engine kicks up under load. I have no idea why an external coil would be used.

 

[wbay]

Now that's confusing. The picture of the (switch box) sure looks like the very old magneto ignition. It has an internal pickup coil and point system. No electrical power is supplied to that system. The only electrical post on that system, simply grounds the system to shut it off. There should also be a wire coming from the tilt mercury switch that shuts the engine down when the engine kicks up under load. I have no idea why an external coil would be used.

Agree about your confusing comment. Searching for parts using the serial number on the mounting bracket does not match up with how the ignition parts look. From some additional googling it looks like the ignition is from a 1971-73 Mercury 500. I was hoping that the red coil could be replaced by a later version before they went to separate coils for each cylinder. Looks like Mercury went through several ignition configuration during the 70s to 80s. Appreciate your response.

 

[GA_Boater]

A magneto and ignition driver in early models look almost identical except for one thing - Mags have a stud for the kill wiring. You don't have that.

I think an older powerhead replaced the '79 powerhead. Look below the timing belt pulley for a stamped serial number, the area circled below. Also some Mercs have a welch plug with the serial number, usually on top or side of the block.

 

[wbay]

A magneto and ignition driver in early models look almost identical except for one thing - Mags have a stud for the kill wiring. You don't have that.

I think an older powerhead replaced the '79 powerhead. Look below the timing belt pulley for a stamped serial number, the area circled below. Also some Mercs have a welch plug with the serial number, usually on top or side of the block.

View attachment 327295

Thanks for the information!

 

[GA_Boater]

Thanks for the information!

Forgive me, I left my manners outside the door.

Welcome aboard, wbay.

 

[1960 Starflite]

A magneto and ignition driver in early models look almost identical except for one thing - Mags have a stud for the kill wiring. You don't have that.

I think an older powerhead replaced the '79 powerhead. Look below the timing belt pulley for a stamped serial number, the area circled below. Also some Mercs have a welch plug with the serial number, usually on top or side of the block.

View attachment 327295

Thanks, I learn something here every time I visit !

 

[wbay]

Thanks, I learn something here every time I visit !

Thanks for everyone's help.

Walter

 

[The Force power]

From some additional googling it looks like the ignition is from a 1971-73 Mercury 500. I was hoping that the red coil could be replaced by a later version before they went to separate coils for each cylinder. Looks like Mercury went through several ignition configuration during the 70s to 80s. Appreciate your response.

In the pictures provided; yours is pre '73 after that it went to individual coils & and a different switch-box (still belt driven)
In '75 or '76 it went to a Stator & Trigger assembly under the Flywheel
They were good solid motors accept setting the max spark-advance etc. is a hassle.
(don't touch it if you don't have to)

 

[Faztbullet]

What makes you think coil is bad as those rarely fail???? Never was a belt driven distributer model with individual coils either all where single coil..orange,red ,green or black

 

[The Force power]

Duly noted

 

[wbay]

Sorry, I mixed that up with the 60hp 3 Cyl.

I appreciate the responses.
I had pulled the coil and checked it with a multi-meter based on this youtube video.

The secondary output showed nothing just like the video.

 

[wbay]

I appreciate the responses.
I had pulled the coil and checked it with a multi-meter based on this youtube video.

The secondary output showed nothing just like the video.

Also what type of grease should I use on the zerk fittings on the ignition driver/distributor assembly?

 

[wbay]

The original issue was no fire to the spark plugs and going through checking wires, components, etc. to determine the problem. Took off mercury switch, disconnected remote control kill wire, etc,