Replacing Ignition Switch for 1961 Mercury 800 6 cylinder

[ErnieH]

I am in need of replacing the ignition switch on my 1961 Mercury 800 (80 HP) which has a single handle control. There seams to be different switches and some are for engines with magnitos. I purchased a switch from a local dealer which states that it will fit most Mercury engines, however it is a 6 post switch that is for an engine with a magnito and the old one is a 4 post switch. Does this motor use a magnito and can the 6 post switch be wired correctly? ErnieH

 

[emckelvy]

Re: Replacing Ignition Switch for 1961 Mercury 800 6 cylinder

The important thing to remember is that the key switch has to supply power to the ignition system when in the "ON" position. When switched to what would normally be the "START" position, instead it should energize both ignition system, and the choke solenoid. And of course the starting function is accomplished via the pushbutton on the underside of the hand rest at the top of the control lever.

Here's a link to a wiring diagram, as long as you follow the diagram you should be OK.

http://www.maxrules.com/oldmercs/Wiring/0_1965a/6.pdf

A meter or test lite will help in getting everything figured out. Sears usually has good sales on their digital voltmeters, even the least expensive would work fine for this task.

BTW the magneto kill contacts in the switch would just be left empty in this application. Most replacement ign switches will have all the extra contacts that would be needed for either application, powered ignition or mag-kill type. You just wire up the ones that are needed by that particular motor.

HTH............ed

 

[ErnieH]

Re: Replacing Ignition Switch for 1961 Mercury 800 6 cylinder

I have a volt/ohm meter and have ran the wires to the battery and starter as well as the electric choke. My control has four wires plus the electric choke wire which is wired thru a separate push type choke switch on top of the control unit. It is just hooked to the battery post and the push switch activates it. The wires have all been sprayed with a gray insulating material so I havn't seen the color of the wires as of yet. On the new switch it has 6 posts, B for battery, S for switch, I for ignition, C for the electric choke which I don't need to use since I have a separate switch and two posts marked M which I assume are for a magneto hook up of some kind. The control unit has a neutral position switch that only allows it to start in the neutral position and not in gear so that wire has to go to the start solonoid. The starter is on the key both with the old and the new switch. So I know which wires would go to the battery, choke switch and starter which leaves two wires to be hooked up, one of which probably goes to the ignition and I don't know about the other. Both switches have three positions, off, run and start and the new switch has a push type choke which I don't need. One of the two remaining wires has continuity to the negative battery cable which I assume is ground.

 

[ErnieH]

Re: Replacing Ignition Switch for 1961 Mercury 800 6 cylinder

never mind, after ordering 5 times from Mercury they finally shipped the right switch, the part number has been upgraded four times and if anyone needs this switch the latest number is 54212A9.

 

[emckelvy]

Re: Replacing Ignition Switch for 1961 Mercury 800 6 cylinder

Hey, I was looking at the old posting and realize now that you have a Full Gear Shift (FGS) 800, not a direct reversing. The FGS would be hooked up a bit different than I described!

It sounds like you've got it pretty much figured out, but I thought I'd post this link anyway, maybe it'll help:

http://www.maxrules.com/oldmercs/Wiring/0_1965a/7.pdf

On your choke, all you'll need to do is tie one end of the separate pushbutton choke switch to the source of switched +12V, and the other wire off the switch goes to the choke wire in the harness.

And of course the ign is still energized in the "ON" and "START" positions.

The starter wire terminal might be "S" for 'starter' rather than "S" for 'switch'. An easy way to check this is to connect one end of an ohmmeter to the "B" battery terminal, the other to the "S" terminal and move the switch to the "ON" then "START" position. You should only get continuity (Zero Ohms) with the switch in the "START" position if that's the purpose of the "S" terminal.

You can do the same thing with the other terminals on the switch to make sure they're what you think they are.

Here's something else strange on these motors, some did use a wiring configuration like the one linked above; others used the later "Merc 1000" etc type of wiring, which actually is a better setup. The older-style harness/switch was connected to allow the alternator wire (to the rectifier) to be 'switched'. This is not a good idea, since when you turn the ign off you've disconnected the rectifier from the stator while the motor is still turning. This can blow a rectifier. Merc figured out that it's better to always have the rectifier connected to the positive side of the battery. Whether you do this at the ign switch or by running a jumper from the rectifier to the large Red cable inside the motor, it doesn't matter.

The other thing is the way the ign is hooked up. Early models bypassed the ballast resistors when starting only, then when the ign switch is released to the "ON" position power would flow thru the resistors. This setup isn't necessary as there's plenty of ign power to start the motor without putting full voltage to the coils (which can burn the points). So, it'd probably be best to eliminate this feature as well. You can do this easily by removing the red-wire jumper between the solenoid and the front ign coil (#2).

This diagram for the more "modern" dual-point distributor ign setup shows the difference from the older FGS ignition system:

http://www.maxrules.com/oldmercs/Wiring/0_1965a/9.pdf

Anyway, sorry about the misunderstanding and hopefully the extra info helps.........ed

 

[Fuzzytbay]

Re: Replacing Ignition Switch for 1961 Mercury 800 6 cylinder

Your switch should only have three terminals for that motor, the old one had four. Also make sure to follow the advice on the regulator hook up, if you have a fast shut down, it will most likly pop your regulator if left hooked up the way it was orignally. BTW any key from merc will work for those motor, that fits into your controller. So if the switch you get is the wrong one, post back I'll give you the how to hook it up.....I know after merc gave me the wrong switch, I just used one from an old controller and made do with my 61 800FGS.