So far I've done Echo 23.6cc engines, Homelite 25 & 30cc engines, a Ryobi 31cc, and a Poulan 42cc on Gas/Glow. At some point in all our beginning experiments, Aeronut reported some detonation in a Ryobi 31cc. We switched to using Premium in the gas part of the mix, and the problem went away. I just now use premium in all my engines. My Poulan 42cc is the only one that has a rpm drop when the glow plug power is removed, suggesting that it could use a touch more compression to be optimal. (Or a touch more nitro in the glow part of the mix.)

But as always, experimenting is great and often leads to useful new information.

Good luck,
AV8TOR