Ignition noise on radio

[thesolarsailor]

Hi All

I have a 1976 A4 in a Newport 28 sailboat. A previous owner upgraded the ignition to electronic, the boat has been in fresh water forever so there is little corrosion on the electrical system. Here is the dilemma:

I cannot run a hard wired radio while the engine is running, I get a serious popping through the speakers which I assume is the ignition system.

I have rerouted all grounds to a single point on the engine, added external ground to the alternator, rewired the 1/2/both switch to meet ABYC standards and the problem has changed by maybe 5%. The antenna leads are run separate from any power leads.

I prefer to fix the problem rather than install a filter on each power lead, any recommendations?

[ndutton]

What type of plug wires are you running, solid or resistance? Is there a noise suppression condenser on the outside of the distributor and/or alternator?

[joe_db]

AM radio?
SSB?
FM?
VHF-FM?
My engine will definitely make noise on MF or HF AM/SSB, but not FM. You can use resistor plugs and carbon spark plug wires (vs. solid copper) to cut down a lot of it.