Rythmic ticking.... 750-4

1980 750-4 LTD.

Took a spin today. Bike runs great and strong. Recent oil change, valve clearances in spec, stock airbox and dunstall slip on pipes.

At idle the bike is purring just fine. I can hear the valves ticking, but nothing extreme. Then, a rythmic ticking becomes noticeable, gets louder, goes away...all within 3 seconds. Wait maybe 5-10 sec and it does it again. Can't tell where its coming from, but if I had to guess I'd go with the top end. Any ideas? The rythmic style really baffles me...plus its a slow ticking, maybe 4 ticks/sec, so it seems slow to be associated with any cam/valve noise.

It's done this the entire time I've owned the bike and I only notice it at idle.

Stupid ideas. Just rambling...

Is it doing it on the kickstand? What about off the kickstand or leaning to the other side? If you plug the emissions, does the noise go away? Increase the rpm's slightly. Still hear it? On your favorite road at your favorite speed on a beautiful day with only the best of friends while passing a Harley, are you still reminded of it?

Seriously, the only one I'd probably check is idle. Bump it slightly and if the noise goes away then forget it like it never happened.

two things come to mind.

1. If you haven't removed the emmissions stuff form the valve covers. It could be the reed valves in the valve covers clicking. That could be kind of random.

2. If your running the stock cam chain tensioner I would remove it immediatly. Could be tesioner is periodically slipping and the chain is clicking. I would be leary of the tensioner letting go.

hehe, I did just that. (the harley part) They were just getting on their bikes after sitting in a tavern all day (why have the bike anyway?).

As for the questions: does it kickstand or none. no difference with the leaning. Never thought of the emissions... I'll have to increase the RPMs once and try it. It's subtle enough you don't hear it while revving, but I bet if I just increase my idle speed to 2k or so I could still hear it.

And to have a gem like this bike for $300, no, I quickly forget about it at times.

When is the last time you adjusted you cam chain tensioner? That's what I think it sounds like .

Well, I have verified several times that the tensioner works (off the bike of course), but how well I don't know. It's the automatic two wedge tensioner type... Been meaning to upgrade, but just a tightwad...

Is my only option the APE one? Just seems pricey for what you get. Did maybe one of the older bikes have a manual one that could fit?

Maybe you could use one from a "new" generation ZR750

apbling wrote: Well, I have verified several times that the tensioner works (off the bike of course), but how well I don't know. It's the automatic two wedge tensioner type... Been meaning to upgrade, but just a tightwad...

I said the exact same thing about my 650, untill it failed on me one day. I was lucky a was a block away from home and limped in. It didn't completely let go but it loosed up a lot, the sound was NOT something I care to hear again.

Buy the part form APE and be done with it.

Done. Just ordered one from Z1.

Would just the tensioner on the outside of the engine be necessary or parts inside the head also? I'm assuming just the exterior bolt on piece but I'd like clarification. I'm considering this also for my '79 650.

I've never had the head off and inspected anything... That would be a kind of expensive little exploratory surgery...