61 Merc 500 vacuum switch?

[fmfmedic]

Hello. I'm working on a 1961 Merc 500 4 cylinder engine. Don't have a manual for this motor, although I have ordered one. It hasn't run for several years, but it is complete, fairly clean, wires mostly in good shape. Was putting it back together when I noticed two wires, red and black, with the factory disconnect, which don't seem to go anywhere. The red wire comes from the ground on the starter and the black from the hot side of the starter. They go through a wire holder just aft what looks like vacuum switch mount and end on the starboard side aft, and there are no wires to connect them to. There is a wire holder at number one cylinder, oriented vertically, but no wires, and no loose wires anywhere. Where do they go?

Also, there is no vacuum switch on the mount, (starboard on the block). At least it looks like a vacuum switch mount. It is identical to the vacuum switch mount on my 1969 Evinrude. I've looked at the online diagrams and can't find anything there. What is it and should there be something there?

 

[coolguy147]

Re: 61 Merc 500 vacuum switch?

no vacuum switch.

i would get some oil in the cylinders and tilt the motor up so it will get to the bearings.

check compression.

the biggest problem on the motor is corrosion (wires bolts nuts) and parts. check the ignition system welll over.

 

[merc850]

Re: 61 Merc 500 vacuum switch?

Those wires in your first pic don't belong there, if you connect them together they will melt when you start motor. The switch against the block in pic 2 is a mercury tilt switch that momentarily shuts off the ignition if the motor hits something while underway and tilts up too far. You can test this by tilting the motor running in neutral, the motor should stop.

 

[fmfmedic]

Re: 61 Merc 500 vacuum switch?

OK, I'll take the wires off and see what happens when I start it. There was a third wire, but it goes to the choke.

I was surprised to find that very few of the wires were corroded, or with brittle insulation, I only had to repair/replace two of them. The attachments and bolts were barely rusted and came off easily. I cleaned them up and put them back. I also used liquid electrical tape on all wiring connections after cleaning everything up. Compression is good, especially after putting Deep Creep in the cylinders, which have significant carbon on them. The big thing was the carbs, both floats were stuck shut, too them apart and cleaned them up. Will put new kits in them after I get it running, assuming I can.

Thank you both.