I am at 6200ASL here in Colorado Springs. I plan to use 30% heli fuel for the extra power. Should I also use it as my break-in fuel, or should I start with a gallon of YS 20/20? On all my other YS engines I always ran the 20%, but I was at sea level, and my experience with R/C car engines is to break in with the exact fuel you intend to run, but they are ABC engines and their heat cycle is crucial, and the YS is ringed, so does it matter?

It really doesn't matter what you start with. I would just go ahead and use the 30 heli. The engine will love it. We use the same here in Hooterville (5000 ft).

Lots of snow today, sending it to you in a couple of days (sorry).

Good Flying!

Dave, along these same lines, would you recommend breaking-in with a fuel that contains a small amount of castor, before switching to pure synthetic? If so, how much castor in the fuel, and how many gallons of it before switching to pure synth for a new YS 110FZ?

Thanks,
Kurt

Castor is YS engines can cause the regulator to gum up when the engine is stored. In addition, burned castor builds up on the exhaust valve at a high rate, and at some point the engine will need to be taken apart to clean the valve. Buildup with the synthetics is at a much lower rate.

Thanks, Dave, that's what I figured. Well, it's tuesday and still no snow...hopefully it won't make it!

Hope you don't get the snow. It has been a serious pain in the a--!