Wires off the M-8

[Solex 27]

I have a Magnum 8, spec number 301511 that will be used to re-power a C-81. The motor has two black wires and one white wire coming off the engine all going to a 3 position connector. Can you tell me the function of the wires? For example I assume the white wire must be for the ignition module? The plan is to build my own harness based upon the 308-8 drawing, but not to wire in any kill switches at least for the short term. The plan is to use a 308-8 key switch as well. The  P.O. removed  the seat, PTO and clutch switches.

[pfrederi 18,566]

The white is most likely the magneto kill wire..Make sure you do not apply any voltage to it!!! You will need a new ignition switch for magneto ignition that grounds the white wire to turn it off.  The two blacks are probably AC from the stator and go to the voltage regulator

[wrightorchid 261]

Review the wiring for the magnum powers engines, as they are a bit different.  Save Old Iron most likely has a basic wiring diagram, and you will need the correct ignition switch.  You should be able to search on that within the forum.

[Solex 27]

So that takes care of the the white wire, it goes to the M terminal on the switch. Therefore now just two remaining, according to the drawing, one of the black wires goes directly from the engine to the light switch and then on to the lights. The other black wire goes to the rectifier or R terminal. So I have a 50/50 shot of getting it right. Is there any way to test in advance? Can I do any harm if I guess wrong?

[pfrederi 18,566]

...  From your description sounds like your magnum motor has the 3 amp unregulated charging system.  The head lights on it run on current directly from the stator.  One wire is regulated one not.

Edit:  Your head lights run on AC and there should be about 15 volts available according to the magnum manual.  According to it you should have a yellow wire for the lights and a black one for the charging system.. Work your way back toward the engine one of the wires should have a diode in it...That is your charging system feed.
 

Edited September 1, 2015 by pfrederi

[Solex 27]

Thank You, I will remove some the tin, and hopefully discover a yellow wire or a diode.

[pfrederi 18,566]

I DO NOT tHINK YOU NEED TO REMOVE ANY TIN.  I looked at my 310-8 with the same system the diode is only 2-3" back from the connector under the plastic tube that covers the wires coming from the engine

[Save Old Iron 1,571]

If it is a three amp system, it will wire up like this



The wire with the "bulge" in it will be the diode in the charging wire, the other wire will attach to the headlights.