TR6 sticky valve when hot

have a sticky valve when hot on my tr6 motor,did not do that before,just started today,any remedy other than pulling the head? first cylinder seems to fire in the exhaust manifold-at least it sounds like it.
any help is much appreciated
Thanks

What makes you think it's a sticky valve?
Do you hear a loud clacking associated with this?
Have you checked valve lash, and looked at, manually compressed, valve springs?
Valve springs can be dealt with on the car if you know what you're doing.
Flat cam?
Bent pushrod?
Bad rocker arm?
Cracked head or valve seat?
Bad distributor cap, broken rotor, causing spark to occur at inopportune times?

I mean, I belive you that you have a sticking valve. Just need to properly identify what it really is before we tear it down, can't find the source, and put it all back together to identify source and then tear it down again.

Thanks for all the input,will do more checking as suggested by you,just wanted to get some ideas before tearing it down.valves have been adjusted 35 miles ago,but spring could be broken,that would probably make the same symptoms-would make you wonder why it broke though.

And a crack in a seat area as it opens. When hot.
All sorts of things.
Does it clack when this happens, like an actual valve sticking in a guide?
Might want to run a valve lash hot....not so much to get absolute values but to see if something is radically different when hot.

I had a broken valve spring. Showed zero compression in that cylinder.