Topic: About coils

[Lars]

I Imported a US Honda Cb 550 K76. Tuned it up, fired up and ran well. Sold it. New owner barely came home and engine would not restart. Checked out the sparkplugs and they were wet so fuel is OK, but no or poor spark on the plugs. Took off the sparkplug caps and determined the ignition cables are in bad condition. New cables purchased and now the fun begins - taking the old ignition cables off the coil. Hm, maybe not ment to be taken off?

Unisolated the new cable like the one I got off. With a little WD-40 and a loop on the cable, I eventually screwed it back in. Hard to know when it is all the way in, though.

Question 1: Did I ruin the coil by getting the ignition cable off??? They are ment to be replaced, yes? No?

Question 2: What is the difference between the coils for i.e. Honda CB 350F, CB 550 K, CB 750 K? Would they be interchangeable, if not for the different way of mounting them on the bike? If they are not interchangable, why not?

Cheers
Lars

[Deltarider]

Hi Lars,

Question 1: Did I ruin the coil by getting the ignition cable off??? They are ment to be replaced, yes??!

Honda clearly didn't anticipate customers replacing cables. I'm surprised so many want to replace the cables as a whole, as these tend to deteriorate at the plugcap end most. Cutting the cable say halfway and connecting some new cable by using the NGK J-1 cable coupler could well be an alternative.

Question 2: What is the difference between the coils for i.e. Honda CB 350F, CB 550 K, CB 750 K? Would they be interchangeable, if not for the different way of mounting them on the bike? If they are not interchangable, why not?

The number of windings differ. Somewhere I've read:

Primary windings     CB750K1/K2     380 wdg.
                           CB350/500       420 wdg.
Secundary windings CB750K1/K2  15000 wdg.
                           CB350/500    13000 wdg.

I don't know why Honda developed different coils. I don't think you will notice much difference, if at all, by interchanging.

[Lars]

Thanks Deltarider. I have got some input on this site, maybe of interest for you, too.

Lars

http://www.xs11.com/xs11-info/tech-tips/repairs/battery---electrical/91-new-wires-in-old-coils.html