Mackay
Power in model aviation.
50 cc Four-Stroke Petrol.

50cc Four-Stroke Engine

At last! The engine you have all been waiting for, four stroke sound with petrol reliability and economy. This lightweight powerhouse weighing just 1.5 kg is mow available for that special scale model, ideal for aircraft from 12- 20 lbs. weight. Its very slim profile and low weight makes it ideal to power aircraft designed for traditional 30-35 cc glow two-stroke engines. Proven Mackay Four-stroke technology offers quiet running for today’s strict noise environment. It is unique in being the only purpose designed petrol model aircraft four-stroke engine currently available. The lubrication system allows inverted installation in the model. Each engine comes complete with a computerised ignition system with automatic advance/retard to enable easy starting, optimum power and low reliable idle It boasts one of the highest power/weight ratios for a petrol engine of this capacity.

Technical Specification:
Purpose designed 50 cc petrol four stroke, Walbro pumped carburettor, computerised electronic ignition (4.8 V Nicad required), weight 1.5 kg inc. ignition less battery.

Recommended props 18/10 (7000 rpm) - 22/12 (5000 rpm). Distance from prop face to: Rear of crankcase 112 mm. Cylinder axis 80 mm. Rear of carb. 155mm. Height from centre-line of crank 127 mm. Crankcase width 65 mm.

M4 mounting bolts width between centres 75 mm

See video here