Hi Bryan / Rendegade,

Yes the YS instructions state oil content as 20 - 23%. Most pilots like their engines to last and would try to provide best conditions for longevity and hence might lean to 23% oil. In fact some manufacturers produce fuel to cater for YS engines using 23% oil. This I believe is partly to allow pilots to stick within warranty conditions and / or for the afore mentioned feel good factor. I think however if depends strongly on what oil you use; maybe there is an oil out there where 23% content is good, but clearly this is not the case with the oils I used, and which are present in most heli fuels that YS use.

I hope to do more work like this on the CDi blends; currently I'm using 25% nitro / 10% KL198 oil with great success and my CDi turns an APC 18.1 x 11 at 7950 - 8000 rpm with idle down to 1500 rpm.

Keith