2019-Dec

Gas Engines

EVOE 10GX2

Mixture: 20:1 (break-in & normal flight)
Propeller: 10x6 (break-in), 12x6 (normal flight)

Break-in Process

First tank of fuel: Set the high-speed needle valve at 2.5 turns out and use the 10x6 break-in prop. Run the engine on the ground for its first tank of fuel and DO NOT go above half throttle. Cycle the throttle between idle and half throttle every minute.

Second tank of fuel: Tune the needle valve to be slightly rich of the peak RPM at full throttle without a drop in RPM. Do not run at full throttle on the ground for more than 30 seconds at a time. Tune the low speed needle valve for a smooth transition from idle to mid-range, go back to full throttle to confirm the main needle valve setting and then fly. During this flight, be sure to be conscientious of extended periods of heating the engine. Be sure to mix-in some cool-down dives and lower-throttle flying.

Note: low speed needle turns the opersite way to the high-speed needle to rich/lean. ¯\(ツ)/¯

Third tank of fuel: Fly the engine at high throttle while performing the recommended figure eight maneuvers. This will help the piston ring and cylinder liner to expand and contract; helping the breaking-in process. Tune the needle valve to be slightly rich of the peak RPM as necessary.

Fourth tank of fuel: Select one of the recommended propellers for normal operation and mount it on your engine. Tune the main needle valve to be slightly rich of
the peak RPM and the low speed needle valve for a smooth transition from idle to full throttle and continue to break-in the engine in flight.

Do not worry about an engine setting being slightly rich during this process. When set correctly, the engine will occasionally sound as if it is misfiring (which it is). During the climbing maneuvers this should go away and might return during the diving maneuvers. If it does not go away during the climbs, land the airplane and lean the high-speed needle by 1–2 clicks, then take off and fly again. Enjoy the break-in process—you are doing a lot of flying.