Boy when they wear out they wear out.
This customer couldn't leave the mixtures alone. Engine stalling upon acceleration or if you get it running good at full throttle dies when going back to idle. It would even idle good unless you were near clutch engagement speed.
I figure it was toast after non-invasive tests show low compression.
This morning I did complete tear down to satisfy for my own curiosity. Found the cylinder plating worn through, galled piston, and a little out spec ring end clearance. Well that a lie as it is .116" when the specs is 0.020 max. How in the world I ever got 115 psi wet compression reading is good question. He even had the wrong plug in it.