[Dirtrack49]

I have used MMO in many engines with good results.
Had a Cessna 120 with a Continental 85hp engine that would stick a valve in the winter cold of the high desert. I use to use what was referred to as the rope trick to get the valve to close. However, after switching from MMO to Rieslone, I never had to use the rope trick again.
By the bye, the rope trick was to shove a rope into the bad cylinders spark hole and bring the prop up to force the arrant valve to close.

Tom L.