At first, I was disappointed with this engine, all my flights always ended with dead sticks, then I re-read the manual and realized that it recommends "hot heat-range glow plug", since then I´m using OS A3 glow plug and WOW!, it is my favourite engine, reliable, consistent and VERY powerfull. And the fuel consumption is the same of my .46 engines, fantastic !!! I love this engine, soon will order another one.