As of yesterday, I have an annoying tickety tack interference on the radio, which reliable sources tell me is due to mag interference and most likely arises from the grounding lead. Both mags are working fine and the pain is that to get at the back of the mags on the Super Cub (0320-A2B) it looks like the engine has to be swung. I'll probably live with this for a while longer therefore, but any comments from knowledgeable parties on this forum would be appreciated -- Genghis, A and C?

QDM

QDMcubed - not an expert myself on this and am not disputing the fact that grounding could be the issue. On car ignition system, this sort of RF interference is usually down to a duff / loose connection on a suppressor capacitor across the breaker. Would still mean getting to the mags, however. When you say the engine will have to be 'swung', assume you're not referring to manual turning of the prop ;) :)

Not difficult really. You probably have an ignition lead breaking down and the noise you are hearing is the leak of the high tension spark somewhere.
Get your mechanic to do a lead test with a high voltage tester and you will find it. Change the lead and all will be well.
The engine on the Super Cub is hinged by removing the cowling and bolts on the left side. The engine will then hinge to the right and getting at the mags to change the lead is no problem.
Have fun.

QDM,

Light Aero Spares can supply suppressors (IIRC they are about £25) I have them on my Pitts and they do make a huge difference.


Stik

Thanks a lot, everyone -- very useful info.

Can I ask if this is a problem with the shielding around the p leads is this likely to lead to a failure of the mag in question? I have a cross-channel trip coming up in ten days and don't know if I can get it fixed before then.

David