I have the heads off my Craftsman 18 hp lawn mower. One intake valve sticks open. It returns to a seated position with a light tap. I have tried to lubricate and heat the stem without success Any Advice?

Prez

What did you lub with? Sticking valves are usually stuck with some really burnt junk so try WD 40 or even something like SeaFoam. Open the valve squirt some in and then get the valve to open and close several times.

I've tried wd40, gunk degreaser laquer thinner, heat, maybe it may take dynamite

The valve spins free in the guide . The valve is horizontal so maybe I'll try draining the oil and tipping the rig on it's side