YS engines are a high performance engine and IMO, any type of high performance engine will perform better, with better quality and higher octane fuel.

I run 30% nitro in all my engines. Only had 2 dead sticks with my YS 140/160's over a ten year period. Glow plugs lasted forever.

I'm now running 175cdi's and still using 30% nitro. They will idle for ages at 1700rpm and then throttle up without any problems.

Most of the flyers i know that are having problems with YS's, are using lower nitro fuel.

I'm positive that the reliable idle and running is helped greatly by using 30% nitro.