Mounting Nut for an Ignition Switch

[FloatsLikeARock]

I'm trying to replace a basic Mercury outboard ignition switch, part number 87-88107A5. The switches that almost ALL vendors offer as a replacement for this switch must all come from the same factory in China. The switch is electrically correct, but the thread size on the part that sticks through the instrument panel is an odd size, and the single mounting nut that came with it is a cheesy POS that I'm afraid will break if I tighten it enough to secure the switch. The original mounting nut off of the old switch, part number 11-879755, is a different thread pitch than the nut on this replacement switch, so it won't fit.

The outer diameter of the threaded part of the replacement switch is about .790 inch, and the thread pitch appears to be about 16 TPI. Too big to be 3/4 inch, and too small to be 7/8. I guess it's metric, and it's an odd enough size that I can't find anything like it anywhere.

Anybody know where I could find mounting nuts that might fit on this switch?

And If I can't find those nuts, where could I find a better quality switch that doesn't have this mounting problem?

 

[airshot]

You might have to put 3 small dabs of silicone on the switch then just finger tighten that nut, once the silicone drys it should be very stabile yet easily removed if needed down the road

 

[Chris1956]

Is this ign switch for a MerControl? If so, that nut doesn't do much. The old ones were recessed with a lip, which I thought was really there to protect the key from being broken when hit with your arm or leg. I guess they held the Ign switch from being pushed it.

You could take the new nut to a HW store and find a replacement. It is likely a std metric nut. You could put some silicone on it as suggested, stick a thin washer under it for added strength and see what happens.

 

[FloatsLikeARock]

Not MerControl. It's just a plain old stick through the panel type switch. My best guess is that the thread is M20-1.5. A nut that size is available from a few places. I would have to cut it in two to get the thickness I need... and it's on a boat, so stainless would be better. Pricey.

 

[Chris1956]

The internet has a ton of supply places for nuts. Verify the thread size and see if you can find a thin brass one.