Intermittent starting issue

[DSA]

Another week, another thing to fix
The issue: when I hit the starter on my '76, sometimes it cranks as it should...and other times, it does not. When it doesn't crank, the headlight does turn off and it stays off as long as the starter button is depressed. There is no sound (specifically no clicking in a dead battery sort of way). Battery reads a strong 12.7V.
And then at random it will start cranking again. I can't reliably reproduce it enough to know what suddenly makes it start working again, or what causes it to stop working.
I did open up the switch assembly and clean all the contacts - that didn't change anything and on hindsight that makes sense - if the headlight goes off when I hit the button, clearly the issue is not a failing switch or poor contact.

Not sure what to try next - any suggestions?

[Shadowjack]

The headlight is a false symptom. The headlight circuit runs through some interrupter contacts in the starter switch so the load is off the battery when starting. Those are separate from the contacts for the starter solenoid.

[Fred Camper]

Watching with interest as one of my wings has the same issue. I just keep hitting the starter button and suddenly it just starts cranking. So something other than the switch being dirty is my opinion. My guess is the solenoid is sticky and then finally moves.

[Lucien Harpress]

Next down the line would be the starter solenoid. Will it reliably turn over if you jump the terminals with a screwdriver? If so, you might have a solenoid on the way out.

[CYBORG]

solinoid would be ny guess as well

[DSA]

Thanks for the replies! I tried to take your advice, and I have an update.

I went over to the starter relay, and wiggled it downwards to create some clearance between it and the boot that goes on top of it, in order to get access to the terminals. Once I'd done that, before trying the screwdriver method, I tried hitting the starter button. My intention here was to wait for the symptoms to surface (i.e. nothing happening when I hit the button), and then immediately trying the screwdriver method; this would be a somewhat definitive way of isolating the issue to the relay and/or its wiring.

Except that I could not reproduce the issue - I probably hit the starter a good 20 times (only for a couple of seconds each time and with a few seconds in between, to avoid overheating the starter) and it cranked every single time. It didn't do this before: I'd get at best 5 successful presses before the issue surfaced again.

I'm going to let it sit for a bit and then go try again. But if it turns out that jiggling the relay around a little fixed the issue, I should carefully go through all the wiring, and clean all the terminals up on the relay.

[CYBORG]

dirty or loose connection on the solanoid sounds plausible

[pidjones]

Look at the way Honda mounted the relay - can opening to the top. A bike not ridden in the rain, carefully washed, and garaged seldom sees this issue. For some reason, Honda chose to mount the solenoid so that, if water should collect on it, gravity will hold it there and help it into the high-current contacts. In addition, the relays are canned because they lead a rough life. A lot of arcing goes on when they break contact, some even weld themselves closed.

[BurnsYoFace34]

Are gl1000 an gl1100 starters the same?

[Fred Camper]

Pretty sure GL1100 starters are shorter, but they do fit on a GL1000 the same.

[Rat]

Correct Fred ..


Gord

[DSA]

Well, can't get the issue to resurface at all, so will call it solved for now.
On the bright side, I took the opportunity to try out the kick starter in case it comes back when I'm on the road. Oddly satisfying to do it this way