190 CN4 – air-cooled four-cylinder boxer engine

Design and Features

It is the most powerful engine in MVVS's offer. Its cylinder unit is based on a proven 50 cc air-cooled engine. 

The exhausts are oriented to the underside, under the engine. Crankcase made by precise CNC machining from solid material. The crankshaft is mounted in four ball bearings. The connecting rod has both eyes fitted with needle bearings. The pistons are made of aluminum alloy with a high silicon content. The piston has a special surface treatment that reduces friction and ensures longer life. Aluminum alloy cylinders have an internal working surface treated with the nikasil method.

The engine is typical for smooth running, easy starts and a flat course of torque.

The preparation of the mixture is controlled by two Walbro carburettors with a choke and a diaphragm pump. The ignition is battery powered with  electronics and a microprocessor controlled ignition timing and with safety functions.

Technical Specification

Model 190 CN4, boxer, 2-stroke, 4-cylinder
Displacement 191 cm3
Air/water-cooled / X
Bore/Stroke 40/38 mm
Max. output (without generator) 20,5 PS (15,3kW) @ 6500 min-1
Practical RPM range 3000  - 5900 min-1
RPM range 1000 - 9000 min-1
Weight (without generator) 4421 g
Spark plug NGK M10 (CM-6)
Fuel Unleaded 95-octane fuel
Lubrication Oil (Mobil Racing 2T) with petrol in mixture 1:40
Recommended propeller Mejzlik 32x12 (2B), 31x12 (2B), 30x13 (3B)
Recommended headers 2x 3426LR
Recommended exhausts 2x 3511 or 2x 3611
Fuel supply 2x Carburettor (HDA189) EFI system
Weight of fuel supply 2x 128 g 400 g
Ignition 2x ICU-B 2x ICU-BI
Weight of ignition 2x 264 g 2x 168 g
Fuel consumption 4000 RPM 5,37 l/hour 3,94 l/hour
Fuel consumption 5100 RPM 7,5 l/hour 4,73 l/hour
Fuel consumption 5700 RPM 7,35 l/hour 7,1 l/hour
Operating enviromental limits 3000 m 5000 m
Endurance time Approx. 300 hours (every 100 hours check) Approx. 360 hours (Check every 80 hours check)
Start-ability X
System programming X
Engine control X
Installation ease X
Electric starter with controller
Ignition 2x ICU-BS 2x ICU-BSI
Weight of starter (and controller) 686 g 686 g
Static thrust  Propeller 30x13 Propeller 32x12
RPM 7000 min-1 5900 min-1
Thrust 45 kg 36 kg