I do not agree that the all synthetic fuels can not handle a lean run as well as the castor blends. I have seen the castor burn and turn brown all over my muffler when the synthetic oils just wipe off without a trace. The muffler gets a lot hotter then the cyclinder ever will.

I have used my Cool Power 30% in 0.049, 0.061, 0.09, 0.10, .15, .25, .32H, 40, .45, .61, .65, and a spiked the fuel for my 1.20 Fs. If you use this fuel you may see some performance drop if you go back to a lower nitro content.

My opinion.

Dru.