I realize that is what Mintor recommends. But my friends at AeroSlave insist that the only problems they have seen in this engine are the ones being run on 15/17 Cool Power. Now this may be a problem only seen on the initial production run of engines so time will tell. FWIW... the guys at Cool POwer told me that the heli 15% is the same as regular 15% Cool Power(the green stuff). Seems it was a change later on and that it just ended up being a marketing thing for the heli users.

I would think that with 20/20 more Nitro means a more open needle setting thus more fuel flow equals more oil in the engine plus its already a higher volume of oil. An addition of an extra head shim would compensate for any compression issues.

WG