Rythmic ticking.... 750-4

apbling wrote: Just check clearances
1 2 3 4
out .15 .15 .15 .15
in .1 .1 .15 .13

Some of these were a loose .15, so maybe .16 or .17. My manual calls for 0.08-.18.

Now, if my clearances were on the loose side, they would make some noise, but shouldn't it get a little quieter once things expand with the heat?

What is the step in your feeler gauge set?
If measured correctly, there should be a slight drag but not loose when checking. Also should not force the gauge in.
Look for any wear marks that look different from the others, maybe signs of Cam follower bucket or cam lobe wearing un-evenly. Cam followers/buckets can dish. Can you access the guides from the top to see if the rear one has any up down/ side to side play on its pivot? You should have your APE either removed or backed off.

The ticking can be the coil... they will make a ticking noise when they start to go bad, usually accompanied with a lose of a cylinder/cylinders. I am not sure why but have read about it on a few places. I would swap with a known good one and see if that fixes the issue. Maybe time to replace them (70 year old coils can leave you on the side of the road)


Have you had the pipes off recently? Old exhaust gaskets seldom go bad (the bolts can loosen but not often) but a bad exhaust gasket will make a ticking noise as well... I thought my head was toast once upon a time, turned out I just needed to tighten the exhaust nuts a few turns (I had changed the pipe and replaced the gaskets, but after a few heat cycles they failed to seal... crank down the nuts and they were fine). Careful not to over tighten the nuts thought, those buggers will snap off on ya and it is a pain to get them drilled out.

Sometimes valves click less while the oil is cooler/thicker, and get louder when the engine attains normal operating temp.

Ticking sound might be high tension arcs to ground, leaking through old hard cracked worn-out plug wires or faulty caps.

May test by running engine in dark garage while spraying water mist over the coils and plug wiring, and watching for sparks.

Good Fortune!

Fixed it...for now.

Everything looked fine and dandy in there. The buckets all have the same wear patterns and looked the same. So I swapped buckets around on all 8 of them, then put the cams in and remeasured... and swapped them some more... and some more, finally getting a combination that all 8 are in spec. (I wrote down what I all did).

Anyway, although 3 of the intakes are right at their tighter spec, there is no noise anymore. I'll obviously have to do some work yet to adjust the intake ones so I'm more in the middle range, but at least for now the damn noise has stopped. I'm not sure what was causing it.

I also took my smog device off and plugged everything up.

Thanks everyone for the help...hopefully I put this one to bed.

Well good and bad. Each onre of those Buckets/ cam followers are worn to the cam lobe it was against, so now moving them will cause a new wear pattern to develop. Might be no big deal as it might be minor, hopefully, but could wear quite a bit on one or more cam lobes/ buckets.
At least you have it narrowed down and if it returns you could shop for a good used set, from a matched up used motor.

good set from a matched up used motor? I'm not sure I'm following you... Are you saying that if I get a new set of buckets that I would be better to use that motor too?

One thing I noticed is how much the clearances affect how the bike idles. My idle dropped a little bit after messing with the intake clearances. They are all at 0.08 and one at .1, so tighter, but more equal to what I had before. My RPMs were about 950k before messing around and were about 800 after. I actually had to adjust the idle a bit at the carbs. I also noticed that the effect of tight/loose cam chain tensioner has less of an effect now.

I meat getting a used set of cam buckets and cams, disassembled and keep/marked with the locations. As each will wear a pattern to the lobe it rides on. That is where the larger motors with the shim on top will be able to change a shim out and have a fresh flat surface for the lobe again, if a new shim is put in. If the clearances are to tight you will notice a loss of compression/ vacuum. On say an old Chevy with an adjustable rocker arm and hydrolic lifter, you could use a vacuum gauge and see the difference a tighter adjustment would make on RPM and vacuum.
Just be sure they are not to tight. After running for a couple thousand miles you may see them loosen again due to the cam lobes wearing into the existing pattern on the buckets/ cam followers.

Yeah, I figured in the next two months I'll check them again after I get some miles on them.

So, if even bucket wears to it's lobe... what keeps the bucket from rotating, say, 90 deg when I take them out to swap shims. Would it just rotate on it's own and go back to the wear pattern? I could not see any wear patterns at all on the buckets. There was wear from going up and down and wear on the top, but all around the bucket.

They should rotate around under normal operation, this is one reason I thought as the noise came and went, that it could be located here. Engines even are supplied with whats called a "Valve Rotators", which actually will rotate the valve on the seat. But most are designed to just contact just slightly off center so when the lobe wipes across the top of the follower it will rotate it, so hopefully even wear occurs.

I wonder if it's from the actual swapping around or the difference in clearances? Also, maybe it was that smog system?

Like torreyJ said, I classed it up with JB weld. You can't even see it, so eh, who cares.

Guess what. Took the bike for a spin this morning. Get to my destination about 10 min after 55 mph riding...the SOB is ticking again!

So I come home and as I downshift I also notice a buzzing/vibrating sound and it's RPM related. Maybe about 3-4k I notice it, but only on a harder downshift. I played with my tank and tach, no difference.

So I roll it up in my driveway and contemplate backing my truck over it. My truck needs a new tailgate, and well, ya know the story on the bike...so maybe two birds, one stone? hehe...anyway, its not ticking! I blip the throttle a few times, and I can faintly hear it doing it, but not as regularly and it seems to have migrated from the left to the right after my bucket swap.

SO... since I notice the bike does not run as nice now (I think the intake valves are all a bit tight, but close) and I got this buzzing sound and the tick is still around, think I should just go back to my original setup (which I have 2k+ miles on w/o issues) and just hope it doesn't get worse, and if so, start shopping for parts/new motor?