Topic: valve noise...still.

[setdog]

Hello
75 cb750 k5. ~16k miles.  Great to ride except for the tapping noise.
I can only describe as tapping or clicking. Its not grinding or rubbing or rattle.
Its not intermittent, it very well timed. And sounds like its coming right from the head.


I keep thinking its the valve clearance.  But after numerous attempts to adjust I just
Can't seem to get rid of it.  It sounds like metal tapping in time with rpms.
Clearances are .02 intake, .03 exhaust and pretty damn well measured.

I read elsewhere it could be the cam followers.  Might the timing be a little off?
Could poorly set timing cause this kind of clicking?

I believe I'm just an adjustment away from eliminating this sound. 

Otherwise bike running great.

[flybox1]

cam chain adjusted?

did you top off your tune-up with an accurate vacuum sync of your carbs?

[setdog]

I did not re-synch carbs this time around.  Not supposed to synch unless carbs are warm, so I'd have run it after the valve adjust.   

Didn't think carbs can be connected to this noise.

[thep1pe]

Did you check your exhaust flange gasket. It can make a clicking noise if it's slightly loose.

[LesterPiglet]

You have cam followers? 
thep1pe may have something there, a loose exhaust makes some strange noises sometimes.
 

[Vinhead1957]

Check the inside of the tappet covers?   May be hitting on the inside

[george]

All previous answers are things I have heard making noise on my K8 , ++ one one a proper carb sync . Also , I suffer from clutch rattle, very annoying especially when cold . In neutral pull your clutch in and see if the sound changes .
Cheers, George

[AJK]

Hello
75 cb750 k5. ~16k miles.  Great to ride except for the tapping noise.
I can only describe as tapping or clicking. Its not grinding or rubbing or rattle.
Its not intermittent, it very well timed. And sounds like its coming right from the head.


I keep thinking its the valve clearance.  But after numerous attempts to adjust I just
Can't seem to get rid of it.  It sounds like metal tapping in time with rpms.
Clearances are .02 intake, .03 exhaust and pretty damn well measured.

I read elsewhere it could be the cam followers.  Might the timing be a little off?
Could poorly set timing cause this kind of clicking?

I believe I'm just an adjustment away from eliminating this sound. 

Otherwise bike running great.

I wouldn't worry about it. If your lash is in spec (or even 1 thou loose as HondaMan suggests for longevity), then don't worry about it.

Out of my 8, I have 1 that has a slight tick to it. If I accelerate, it even goes away and i get no ticking at all, but seems to be there on constant rpm's. I think its coming from #1 somewhere. All of my lash is perfectly in spec as yours.

Unless your real pedantic, i wouldn't worry about it and just enjoy the bike. Thicker oil might even eliminate it & something to try if your keen.

If its something other than lash, like cam chain or something else, then you'll have to take another look.

[seanbarney41]

Did you check your exhaust flange gasket. It can make a clicking noise if it's slightly loose.

+1 on this...it sounds silly and unrelated, but an exhaust leak at the port sounds almost identical to valve train ticks

[Hasenkopf]

this has been discussed before,   sometimes the tappet screws will wear into the valve stem and this will cause extra clearance,   but you can't tell because the feeler is only measuring the flat spots, not the big assed dent in the valve stem.

[bjbuchanan]

Did you check your exhaust flange gasket. It can make a clicking noise if it's slightly loose.

+1 on this...it sounds silly and unrelated, but an exhaust leak at the port sounds almost identical to valve train ticks

2nd this, it is really surprising how much an exhaust leak can sound like ticking

[setdog]

I'll look into exhaust, even tho I wondered if I was being mocked.
I have a new set of  copper crush gaskets too.

[dave500]

hold a length of hose to your ear and the other end wave it around the exhaust flange area,hold a few rpm or get someone to blip the throttle,sometimes a subtle exhaust flange leak wont show till the engine is under load,some engines just have a tick,even a worn tappet once adjusted can cause a sideways action/glance off to the rocker arm making it tick,short of looking for a worn adjuster or valve tip thats as far as it goes.

[iron_worker]

I'll bite. First thing that strikes my eye is the numbers have no units. Did you set them to .02 and .03" If so, that's 20 and 30 thousandths of an inch which is 10x what they should be.

I can't remember exactly what the stock valve lash numbers are but my CX1 cam required .004" / .004" or .1mm / .1mm. I would imagine the stock cam would be .002" / .003" or .05mm / .075mm or so.

So first of all, check your units and check your decimal place!

... yes I am an engineer. lol Units and decimal places cause more errors than I care to imagine.

IW

[setdog]

The valves are not set 10x what they should be.

I will try this, I found on another thread.

set each cylinders tappets separately,rotate the engine slowly in the run direction with the plugs removed and watch as any inlet valve closes,then bring up that cylinders t mark,set those tappets for that cylinder,rotate again and watch as another inlet valve closes,bring that cylinders t mark up and set that tappet pair,continue untill all four sets are done,ignore that stupid short cut chart for setting multiple cylinders,most people get confused with it.

[dave500]

The valves are not set 10x what they should be.

I will try this, I found on another thread.

set each cylinders tappets separately,rotate the engine slowly in the run direction with the plugs removed and watch as any inlet valve closes,then bring up that cylinders t mark,set those tappets for that cylinder,rotate again and watch as another inlet valve closes,bring that cylinders t mark up and set that tappet pair,continue untill all four sets are done,ignore that stupid short cut chart for setting multiple cylinders,most people get confused with it.

that looks like a bloody good and easy way to get it correct!

[kghost]

The valves are not set 10x what they should be.

I will try this, I found on another thread.

set each cylinders tappets separately,rotate the engine slowly in the run direction with the plugs removed and watch as any inlet valve closes,then bring up that cylinders t mark,set those tappets for that cylinder,rotate again and watch as another inlet valve closes,bring that cylinders t mark up and set that tappet pair,continue untill all four sets are done,ignore that stupid short cut chart for setting multiple cylinders,most people get confused with it.

That's very true.....

I've always set them one at a time.

[setdog]

Seems like a wise method, going from memory the manual doesn't suggest each one by itself,
Instead the manual suggests 4 valves, rotate shaft, then 4 remaining valves.

So I'll give it shot, however if it works to quiet this clicking, would it suggest some kind
Of misalignment elsewhere in the engine?