I use the red Omega 10% fuel in my OS 120AX and have had no problems and plenty of power. I pay $13.00/gallon when buying a 4 gallon case. I did put a Perry pump on my 120AX and moved the tank of the Venus back to the CG. I did have to lean the low end 1/2 turn and re-adjust the high end but it starts and runs great. I do like a low idle for landing this floater, so I have used the flap switch on my JR system and mixed a higher idle when the switch is up and a very low idle when I lower the flap switch; works great.