This engine is not toy. For your own safety, please read the manual carefully before operation. DLE is not responsible for all injuries result from the use.
Before every use, check the engine assembly, propeller and airframe carefully for loose screws and nuts. (Loctite242/243) is strongly recommended on all the screws.
During the break-in process, engine must running with shock absorber installed. Or the engine will be seriously damaged by vibration.
Always stand clear of and behind the propeller; never allow anyone including yourself, to be in front of or to the sides of the propeller when starting or running the engine. Anyone near the engine should wear protective eyewear. Do not wear loose clothing near the engine or propeller