Topic: dohc 750 regulator/rectifier question-TT?

[Jay B]

I'm just finishing up reviving a '79 CB750LTD my brother bought new in '79, last licenced in '88. It has 2 elecronic gizmos which I assume to be the R/R. These are cast peices with wires coming out, and a black potting material sealing everything in. The potting material has degraded with age, most of it has flowed out as kind of a nasty tar like mess. They must work though, I'm getting about 14.17v at 4k rpm. Can I just fill the castings in with a 2 part epoxy to reseal them, or what would one use to do this? TIA

[jdigga]

If you're referring to these then they're spark ignitors.



The R/R looks like this:



From a post on the CB1100F forum:

The potting compound is there to protect the electronics from the elements. If you let it all ooze away, moisture will get in and render your spark generators useless. While you have them out, clean and degrease them thoroughly, then seal with high-temp black RTV or the epoxy of your choice. Just make sure the sealant will withstand high temps (them puppies can get HOT). Speaking of hot, as long as you're in there anyway, consider a heat sink or alternate mounting to dissipate heat better. Moisture and heat are electronic's worst enemies.
John M

[Jay B]

The spark ignitors are it. Obviously I don't know much about dohc electrics. I'll get them cleaned up and reseal with some hi-temp RTV. Thanks a bunch, that's just the info I needed to know.