After the gasket issue was resolved, the Brillelli 25cc mag has been running "Perfect". No midrange problems, just running smooth as silk, at any throttle position. I couldn't ask for a better engine for my Ultra 120. If your looking for a economical engine, Brillelli is a good choice.

Engine installed on: Ultra 120 wt 13.5 lb apc 17 X6 2100 rpm idle 8200 rpm hi after the 15 flights I use Mobil 2t 2 cycle 60:1
16 oz tank with 1/8" tyron fuel line --- flight time on the tank is approx 25 min.
Idle needle position is 10 o'clock Hi needle position is 2 o'clock
With a thicker gasket between spacer and engine corrects the air problem.
If you use Du-bro 16 oz tank with 1/8 tyron, don't use the brass tubes that goes with it. It fits ok
but it will have air leaks. Drill out the plastic connector and fit a 1/8 tube.

GrifMode4