Valve goes in and out of adjustment randomly

[DogBunny]

I thought of elephant's foot adjusters, but to install them you have to take the top half of the head off, so you may as well just put a new valve in, same amount of work. I also think that I have read on this Forum that the elephant's foot adjusters don't rotate the valve, but I'm not sure and don't know.
This is the kind of repair that I never do for a bike that I intend to sell. I have no idea what the new owner is going to do with it. Maybe he's going to immediately tear it apart and put a 750 kit in it. Maybe he's going to let it sit in his garage for another 20 years. Maybe replacing the valve would be the perfect father-son afternoon project for him. The bike runs plenty good enough as is for me to sell it with a clear conscience.

 

[plane_ben]

I just rebuilt the top end and valves on my rephrased motor. Initially, I had the original valves refaced and left the stems alone as they still looked good. Then I read all the posts about removing the hardening and that the valve faces wouldn't last. So I installed new stainless valves from Mikesxs, new guides, new three angle seat grind, and did the elephant feet adjusters. Since running, I've put maybe 700 miles on the engine. The engine makes considerably more valve train noise with this stuff done to it than my stock engine with no modifications to the valve train. I don't know if I can attribute the extra noise to stainless valves, or the elephant feet. I'm leaning towards the elephant feet adjusters because I also run VWs with them, and I have a louder valve train than I did in stock configuration.

As far as the valve rotation caused by the valve adjuster screw, I'm sure that is for added benefit to insure the rotation is there. But I remember discussing this with my Dad when he was alive. Valve springs by their very nature of the twist put in them will rotate valves slightly during operation. The way he explained it to me is that under normal operation of depressing and reseating of the valve, there is milli-second periods where there is slack enough on the keepers, valve retainer, and spring are loose. Then when the tension re-grips, the natural twist of the spring slightly rotates the valve. This theory may be wrong, but my Dad was a pretty sharp cookie and rebuilt engines his entire life.

 

[mrriggs]

As far as the valve rotation caused by the valve adjuster screw, I'm sure that is for added benefit to insure the rotation is there. But I remember discussing this with my Dad when he was alive. Valve springs by their very nature of the twist put in them will rotate valves slightly during operation. The way he explained it to me is that under normal operation of depressing and reseating of the valve, there is milli-second periods where there is slack enough on the keepers, valve retainer, and spring are loose. Then when the tension re-grips, the natural twist of the spring slightly rotates the valve. This theory may be wrong, but my Dad was a pretty sharp cookie and rebuilt engines his entire life.

Your dad must have played with a Spintron, or at least seen the videos. Pretty wild stuff.

 

[plane_ben]

Your dad must have played with a Spintron, or at least seen the videos. Pretty wild stuff.

He may have mriggs. I never had a clue to the depth of that man's knowledge.