Topic: Ticking valves after valve cover removal and adjustment

[drj434343]

So my maintenance saga continues on the 71' CB500.  After removing the valve cover and confirming my chain tensioner worked, I reinstalled the cover and adjusted the valve clearances.  3 of 8 were too tight, almost no clearance, the rest were OK.  Got all the intakes to 0.002", 0.003" for the exhaust.

Engine starts and runs great, but I've got a valve click I didn't hear before the removal.  It appears to come from the cyl 4 valves and is loud enough to hear while siting on the bike, although it kind of fades in and out while it runs.  I can hear clicking valves on the cyl 1 side but I have to put my ear pretty close to the engine to notice it.

I've rechecked the clearances and they still look good.  I have a history of doing these adjustments on car engines, and the valve clicks on an old Volvo engine are loud enough to hear in the car.   However, this noise here is new and has me wondering.  Definitely louder on one side than before. 

Anything I should consider here?  How loud is too loud?

[Vinhead1957]

Absolutely sure of the T position when adjusting?  Double check and make sure the valve is totally closed.

[drj434343]

The marks go by in this order as I crank with the kickstarter:

1.  The twin full advance marks
2.  The F mark
3.  The T mark

I've been aligning the T mark.  When I got there, the "closed" valves had enough play that I could wiggle them a bit, so I felt they were fully closed.  If there's pressure on the rockers at all, they're totally immobile.

This started when I removed and reinstalled the valve cover, but I can't think of anything that I would have done to make this happen.

[lucky]

You can do a quick check like this:

For the intake valves try inserting a .003 thickness gauge. If it slips in that is your loose valve.

For the exhausts try a .004 thickness gauge if it slips in then that valve is loose.

You should always use this method.
Also: A loose ticking valve will cause no damage, but a quiet tight exhaust valve will burn up and crack.

Also if any valves re too tight it can actually keep the engine from idling correctly or at all.

[Old Scrambler]

Did you replace the cover gasket and the adjuster-cap gaskets?  If not, check the inspection cap on the loud value to see if the valve is hitting it. I had that happen on my 750 so I installed a new gasket over the old unit on one cap to solve the problem.

[drj434343]

That's an interesting thought.  I went back out and ran it while slowly loosening each cap to see if the tapping went away, but none of them seemed to affect that.  Perhaps there's rocker contact on the main cover.  The cap o-rings and cover o-ring were all pretty flattened, probably original, so I can imagine that when I re-tightened, everything settled even lower than before.  I've ordered a whole new set to lift everything back up a bit.

My clearance checks do involve one size larger fit check, so I'm pretty confident I've got those right. 

Perhaps I'm just being too sensitive to the normal valve train signature that is now apparent after loosening too valves that were way too tight.  Would it be normal to be able to detect slight valve ticking sitting on the bike at idle without a helmet?

[lucky]

These engines from 40 years ago do make some noise, unlike a modern car engine.

[Schnell]

Properly adjusted valves on my old airhead sound like a coffee clutch of rabid squirrels knitting furiously.