Outer Limits 4x4 Board

Hey,

Has anyone out there had an issue with a 3F popping when its warm?
I've heard it could be worn exhaust valve seats?

I did when on LPG, adjusted the valves, new plugs,leads and a timing adjustment and no more problems.

Adjusted valves found 3 and 4 had tight exhaust valves... adjusted them up.
no problamo