Allow us to introduce our series of Gas engines the Avionic 50cc Gas engines, starter required and with excellent acceleration.

Specification:
● Number of cylinders - Single cylinder
● Output volume（cc） - 50cc
● Single cylinder and stroke（mm）- 43x55mm
● Engine's rotation direction - Left handside rotation (Subject to the result of power take-off)
● Power/rotate speed（kw/min） - 3.9/7500
● Minimum idling stabilized speed（r/min） - 3500±150
● Gasoline - unleaded gasoline
● Engine oil (lubricating oil) - Special purpose two-stroke engine oil or FC lubricating oil
● Gas/Oil Mix: use 20:1 during the 15-hours of break - in / initial run of the engine and 25 to 30:1 is used after the 15 hours
● Spark plug gap（mm） - 0.4 - 0.7 mm
● Dimension of the engine （mm） - 163 x 153 x 170
● Discharge direction of cylinder - Dischanrge to the left (Subject to the result of power take-off)
● Net weight（kg） - 1.7Kgs
● Ignition Battery: 4.8-6.0V NiCd or NiMH, 6.6V LiFe or 7.4V LiPo pack (LiPo use requires voltage regulator.)
● Ignition: Rcexl CDI 
● Carb: Walbro

Propellers: Be sure to start out with a smaller “Break In” prop when the engine is new.  Larger props will give more vertical performance with light planes, and less vertical performance in heavier planes. Lower pitch props are best for WWI planes, higher pitches for WWII fighters.

Break-in: Use a break in prop. Install the engine into the plane. Tune the plane on the ground before the first flight, then fly the plane around gently for the first few gallons. Do not go to full throttle operation for more than a few seconds until you have a few gallons of gas through the engine. Do not break-in the engine on the ground for 2 gallons. It is best to fly the plane because more air goes over the engine and keeps it cooler. Heat is the big enemy during break in. It is best if the cowl is baffled to direct the air onto the engine. Using a small prop reduces the load. Keep the plane moving for the first few gallons. No torque rolling!!! I know it is tempting because you can torque roll at ¼ throttle, but the engine will overheat until it is broken in. There is more friction between the piston ring and piston with the cylinder wall until they have a chance to wear in. 

First flight: Following the break in procedure above, start the engine using the factory needle settings. Leave the cowl off. Let the plane run on the ground for a minute at a high idle. The engine starts to break in quickly, and you may notice the rpm increase on its own. Run the engine up to full throttle momentarily to see if the needle valve settings are correct. Don't run the engine too rich. A little bit of a rich burble on occasion is best for the first flight. Be sure the idle is reliable and low enough to land. If the idle is too high you might run off the runway and damage your plane, so be careful to get the idle as low as possible. Be prepared to kill the engine if necessary because the idle speed will increase as the engine breaks in. After the first flight, the engine will be noticeably different already. After a few flights you will be ready to tweak the needles and go full bore. 
Never go to full throttle while the engine is cold. Let it warm up for 30 seconds before you start hammering the throttle.

Suggested props
22x8, 22x10, 23x8 & 23x10


Break - in Video