Mag reading zero

[WhiteEagle]

Hi All,

I have a Aquilla 582 Blue top, digital instruments. Started her up, tested the mags. The Mags both work independently like they should, but on the one mag no reading, just 0000RPM (still running smoothly). Any suggestions?

[justin.schoeman]

Sounds like the thacho is wired to the mag. Good thacho pickup, but has the downside that you can't measure mag drop... You would need to use an alternate thacho pickup.

[WhiteEagle]

Thanks Justin, is it just loose wiring or is something broken then? Not that mechanical minded as I wished.

[Dobbs]

Agree with Justin, if you look at your four spark plug leads, you will in all probability find one which has a piece of wire wrapped around it, and if you follow it back to the panel, you will see that it leads to the tacho. So when you test the one mag, there will be pulse to the plug which the tacho pick up will see, but when you test the other mag there will not be a pulse going to the plug, and the tacho calculates 0 rpm. If you are comfortable that you can identify a slight drop in rpm, I woulod leave it, but if you insist on being able to confirm the exact mag drop - then an alternate pick up must be used