Moki engine general construction consists of an investment casting using dense, high strength aluminum alloy for the crankcase, front housing and backplate. The front housing is bolted to the crankcase with four screws. So is the backplate. This construction allows very easy assembly. The single ring high silicon alloy piston runs in a hardened steel sleeve which is clamped at the top between the crankcase and the cylinder head. This way, the sleeve can expand freely when it gets hot. Porting is of Schnuerle type with added boost port. The connecting rod has bronze bushings. The prop drive has a single central bolt with nut to clamp the prop.
The glow engines are designed for use with FAI fuel (80/20 methanol/oil, no nitromethane)
The gasoline engine version has increased cooling surface. The raised head has deep, large vertically spaced apart cooling ribs, so that the airflow direction does not affect cooling efficiency. The connecting rod has needle bearings.
PRME supplies the engines with RCexl ignitions. These ignitions have a two year warranty period. (On customer request, a SV-CDI ignition can be supplied instead).
The completely RFI shielded ignition is factory set to fire the CM6 sparkplug at about 23° - 25° before top dead center. Ignition advance and retard is automatic. Ignition weight is 145 grams. Mean current draw is about 500mA.
In these high specific power engines, only premium gasoline fuels should be used with oil ratios of 1:20 (running in) to 1:40 . Use only high quality Synthetic two stroke oils.

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240 gas 40cc

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A slender 60cc in line twin for narrow cowls and extremely low vibration levels. This low vibration is not only due to the well balanced design of opposed moving pistons, but also to the 180 degree firing sequence. This halves the torque pulses, which is an advantage over opposed boxer engines where both cylinders fire at the same time. Each cylinder having it's own induction system eliminates the uneven mixture distribution that plagues boxer engines.
The gasoline engine with generous, deep cooling fin design makes the engine use all available airflow from all directions for easy cowl baflle construction.
Manual
Dimensions

This engine has been run in a test using extra long headers (30cm) and TD30 canisters. The engine needs quite a few choked flips before it will start. Subsequent starts are first flip, even when cooled down for three hours. Pulling a large wood 24x10 was very impressive and without any signs of distress. See the test power graph here

The engine smoothness is incredible! Turbine-like.

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