Wiring at the magneto...

[Michael Burbidge]

My engine has slick mags. I've looked around a bit and cannot find information on which terminals on the mag are for what. I understand and have read the information about how to wire the mag to the switch, etc. I just don't know which screws on the magneto are for ground and which for the p-lead.

Here's a picture of my magneto. I've labeled each of the screws with what I think they're for.



I'm guessing the nut with the fabric washer is where I connect the p-lead. I've labeled that P-Lead. The screw marked GND is actually marked GND on the magneto. I'm guessing that is ground and where I would wire to ground on the mag. The one that confuses me is the one which I've labeled "Unknown". What is that for?

The screws appear to be torx drive. Do you happen to know what size?

Thanks for the help,
Michael-

[az_gila]

Don't worry about "unknown"

The other two are correct.

[Jim P]

Michael, your UNKNOWN is just a vent cap, nothing goes there. Assuming you have a shielded wire, you can use the ground to ground the end of the wire shield.

[Michael Burbidge]

Thanks.

One more question. Sometimes I'm not sure how to secure a wire firewall forward. This is one of those times. These are no other wires in the near vacinity to help secure the p-lead. Here's a picture. It seems like that 20 awg wire would break after awhile. Suggestions?



Michael-

[rv9av8tr]

Hard get a "perspective", but it looks OK. You might use shrink wrap around the leads to provide more flex support. I didn't use anything less than 18ga because of support reasons and the ability to get a good crimp on lug connectors.

[floridawing]

Hello, PM sent

[DanBaier]

Looks okay.

A good idea to leave some slack for the engine to move a bit in the mount without tearing everything apart.

Dan

[brad walton]

Remember when wiring the magneto to a switch, off or open on the switch will be ungrounded at the magneto, and thus the magneto will be hot. On or closed at the switch will allow the magneto to be grounded and not producing spark. I made that mistake initially.

[cln1owner]

I would also suggest a rubber boot on that P-lead terminal.

[N427EF]

The unknown Vent port can be used to hook up a fresh air hose.
Rather than just direct a hose onto the housing of the magneto, take the cap off and direct the cooling air right into the magneto where it does the most good.
If you remove the cap you will see a nut of sorts with 6 holes in it.
I removed this nut drilled out a hole large enough to accept a pipe nipple that would accommodate the inside diameter of a fresh air hose from the top of the engine plenum.
The pipe nipple is simply glued in with JB weld.
This magneto cooling idea is something that everyone seems to do at my airport. While most builders install some kind of air hose directed towards cooling the magneto, I think most of those are not very effective.