The actual oil content of PowerMaster's "YS- 20/20" blend is about 18%. That fuel is approved by YS.

You will find that adding nitro above 20% doesn't gain as much ower as you'd think in the YS, and it can cause overheating problems.

I'd stay away from using 2-stroke heli fuel in any 4-stroke. Its safer to run 10% standard sport mix in the 4-stroke than to try the heli mix. (and the castor content of most 2-stroke blends is high for use in any 4-stroke... Valves can get sticky from castor buildup.)