Low Mag. out put

[Kelly mt]

Well you guys helped me with my generator problem so now I could use help with the mag. I bought a new mag terminal and installed it. I get only 2.5v at idle and 5v at high RPM at the mag terminal post. The engine will not run on the mag. This roadster runs smooth and strong on the 12v battery but misses on a 6v battery. Any ideas or test procedures? PK

 

[Steve Jelf]

How are you measuring the voltage? If it's a digital meter it may sometimes be right accidentally but is probably wrong. You want an old-fashioned analog meter.

One possible reason for low voltage is weak magnets. Another is excessive end play in the crankshaft allowing too much space between the magnets and the mag ring. There are different ways of charging weak magnets. Those are explained in detail in The Electrical System. Do you have it? If not, look here: http://dauntlessgeezer.com/DG80.html.

The most effective way of charging magnets is the out-of-car procedure. As far as I know, the only cure for excessive end play is with the engine out.

If your coils need twelve volts to work, there's something wrong. Six volts should be plenty. They may need adjustment or repair.

 

[Kelly mt]

Thanks for the reply Steve. I'm using a Triplet analog meter. At one point last week I got a 29v AC for a few minutes then back to 8v. I was advised to replace the mag terminal. I did and I'm pretty much in the same spot. I'm going to try the 6v battery again as I found some incorrect wiring and see if I see improvement. I don't have that book now but I will soon. Thanks PK.