Author Topic: Failing coil (Read 324 times)

Ken4004 · « **Reply #15 on:** October 15, 2026, 03:52:55 AM »

Just found this spark plug tester on eBay, not sure if it’s any good but it looks like a fairly basic device so it’s probably OK.

Bryanj · « **Reply #16 on:** October 15, 2026, 06:24:00 AM »

That does not test the spark plug it test wether the coil is giving a good spark

K2-K6 · « **Reply #17 on:** October 15, 2026, 09:21:54 AM »

Put a spare plug in a lead and start it with that held to earth, will verify you've got coil output.

Bryanj · « **Reply #18 on:** October 15, 2026, 11:19:08 AM »

Better if you remove the cap and see how far the spark will jump from ht lead to head, from old memory 3-4mm is a minimum

Ken4004 · « **Reply #19 on:** October 15, 2026, 11:21:02 AM »

That does not test the spark plug it test wether the coil is giving a good spark

Yes you are correct I meant to say coils , sorry for the confusion

Athame57 · « **Reply #20 on:** October 15, 2026, 05:04:20 PM »

I've dug up a coil from the depths of my spares pile and fitted that, all is now fine.

While the spanners where out I put a new starter solenoid in too

as issues had started with that as well.

McCabe-Thiele (Ted) · « **Reply #21 on:** October 15, 2026, 05:49:39 PM »

I've dug up a coil from the depths of my spares pile and fitted that, all is now fine.

Could you see any visible cause on the coil you changed such as casing cracks or HT leads cracks?

Honda-SOHC