Tappet noise (?) doesn't go away...

[OldWrench]

Adjustded to zero clearance many times will cause burnt valve faces, but to the best of my knowledge isn't conducive to uneven valve stem wear, however I'm not a automotive machinist even though I have worked with them for many years. I also understand that machine work can be expensive and sometimes we just can't of don't wish to spend the money. Hopefully once you get all your valves adjusted all will be well.

 

[skiri251]

OldWrench » Wed Jun 29, 2016 12:43 pm[/url]":2afi8ns9]
Adjustded to zero clearance many times will cause burnt valve faces, but to the best of my knowledge isn't conducive to uneven valve stem wear, however I'm not a automotive machinist even though I have worked with them for many years. I also understand that machine work can be expensive and sometimes we just can't of don't wish to spend the money. Hopefully once you get all your valves adjusted all will be well.

Yes you are right. I don't know how long the PO rode this Oldwing with zero clearance.

I got an impression that he bought non-operational Oldwing somewhere, repaired it to be kind of road worthy, then sold it immediately. I saw him replaced the timing belts, he told me he put Randakk's (sp?) carb rebuild kits which I haven't confirmed myself (especially now I have a single carb).

I found stem bearings were goner, rear wheel bearing span and the bore ruined, they were replaced.

Anyway I put around 11,000 miles since then so it must be my doing. I thought I have been adjusting tappets frequently enough because I am kinda sensitive to that particular noise. So I don't know why some of them worn like that.

 

[slabghost]

Too tight valves do not make noise. They tighten over time they do not wear loose.

 

[skiri251]

slabghost » Wed Jun 29, 2016 1:48 pm[/url]":36g36w53]
Too tight valves do not make noise. They tighten over time they do not wear loose.

That's not my experience.

So you are saying tappet clearance is like cancer. Slowly getting tighter and unless you check it periodcally and loosen it, it will get too tight and burns the valve and kill you.

My experience is that tappets make noise over time so I need to adjust them tighter to feel good..
It's not just Oldwings but other bikes like XT500 and BSA with locker arms.

On shim and bucket arrangement like XS750, I experienced that some became tighter while others became looser. I don't know why.

 

[slabghost]

If they loosen at all I would suspect adjusters have moved somehow. Valves beat their way deeper into the head over time allowing the stem to protrude further closing the tappet clearance.

 

[skiri251]

Oh I see, valve seat wear.
Hmmm..
Again mine (BSA, XT500) get louder over time..

Then how come I sometimes hear neglected bikes with really loud tappet noise?
I don't think oweners adjusted the tappets too loose. It's a neglect so they do no maintenance at all.

 

[slabghost]

They probably don't change oil either and dirty oil will wear moving parts ever more quickly. So I'd suspect cam lobe and rocker wear. Both of which should be minimal if the oil is changed as it should be.

 

[OldWrench]

The way valve clearance tightens with with time is from the valve face and seats wearing reducing the clearance between the stem and adjuster. One of the quickest ways to find out if you face and seats are worn it to run a wet and dry compression test.
The procedure for that is run a compression test, note the compression in each cylinder (Make sure throttle is wide open). Squirt some oil in each cylinder and run the test again. If you have a low cylinder and the compression comes up you have rings leaking, if it remains the same you have valves leaking. If the compression is good on the first test, adding oil to the cylinder shouldn't make any difference in wet test. The other method is call a leakdown test, but I really don't recommend it, that is pressurizing a cylinder and then finding where it is leaking.

 

[skiri251]

The last time I did (dry) compression test, a year and 1000 miles ago, they were 170, 175, 175, 170 PSI.

 

[skiri251]

slabghost » Wed Jun 29, 2016 6:36 pm[/url]":3pu3zruf]
They probably don't change oil either and dirty oil will wear moving parts ever more quickly. So I'd suspect cam lobe and rocker wear. Both of which should be minimal if the oil is changed as it should be.

So if the bike is well-maintained, you will never hear tappet noise.. That's against my experience though..
I think I maintain bikes reasonably well.

Maybe it's inherent design flaw of the rocker arms which don't push the valve stem ends straight. There is always some sideway motion and that wears them quicker than the valves dig into the cylinder head.

Actually some of my Oldwing adjusters show this as I photographed.

 

[OldWrench]

That is good compression. Cam lobe wear will increase the gape as will adjuster wear. In the old days before hydraulic lifters we would need to readjust the valves after the first 500 miles because of the valve face and seats wearing in, of course back then we had leaded fuel that added to the problem.