ROTO 85 STG Carb and EFI



Four-stroke two-cylinder petrol internal combustion engine 

ROTO 85 FS AL is suitable for UAV projects within the range of 4 meters and weight up to 35 kg.



Properties of ROTO 85 FS AL

Engine capacity 79,5 ccm

Fuel consumption 

400-920 g/h
Power 3,4 kW
Engine weight from 3260 g
Arrangement of the engine boxer
Cooling air-cooled
Lubrication petrol 95 oct. + 2% oil
Speed 1200 – 6500 rpm
Speed with alternator 2000 – 6500 rpm (limiter)
Ceiling 5000 metres above sea level
Fuel system Carburettor (+Altimeter unit)
Flight modes (lifetime) 200 / 100 hours if TBO is kept



Engine ROTO 85 FS AL can be fitted with

Remote E-Control Management

Roto E-control is an electronic system designed to control the motor generator, which allows the start of the internal combustion engine, charging batteries and hybrid operation, increasing the power of the internal combustion engine (so-called afterburning).

Operating temperature: -20°C to +80°C
Non-operational voltage: 9 - 60V DC
Charging current: 45A
Peak power (10 sec): 4300W
Peak current (10 sec): 100A
Safe voltage: 11 - 55V DC
Operating voltage: 12 - 51V DC
Battery conguration: 12 S
Battery nominal voltage: 43.2V DC
PWM frequency: 20 kHz

Controller thermally connected to infinite heat sink which does not exceed 60°C.

Maximal power dissipation: 20W
Nominal power (60 min): 2200W
Nominal current (60 min): 51A

Controller placed in still air of temperature 25°C.

Maximal power dissipation: 10W
Nominal power (60 min): 1500W
Nominal current (60 min):




Engine Fuel Injection

The Engine Management is designed to manage and control petrol engines from one central Injector to four sequential Injectors.

The Engine Management does not need to be connected to a PC, which is often difficult when running petrol engines in the given environment.

Engine Management - Main Unit

  • sequence control of 1 to 4 Injectors
    • one Injector – one, two, four-cylinder engine
    • two Injectors – two-cylinder engine with sequential control, or
  • four-cylinder engine – one pair = one Injector
    • four Injectors – four-cylinder engine with sequential control
  • 6x temperature input
    • CHT, EGT, water, oil sensors
  • fuel level sensor – capacitance fuel sensor
  • fuel consumption measurement
  • 2x voltage measurement
    • Main power supply
    • Servomotor power supply
  • fuel pressure measurement with possibility Fuel Pump regulation
    • constant (adjustable) power Fuel Pump – mechanical press. regulator
    • automatic Fuel Pump – adjustable fuel pressure
  • wideband oxygen sensor
  • ECO and MAX Power mode
  • timers
  • choice litter or gallon
  • choice °C or °F
  • Export data to flight computer

Controller Module


Alternator 300W Alternator 600W
PMG ( Permanent Magnet Generator) 3 phase output
NdFeB magnets
Voltage curve 14V/1000RPM (possibility of rewinding according to client)
Diameter 101mm
Thickness 22mm 25mm
Weight 450g 550g
Out. Power at 3000RPM 300W 430W
Out. Power at 6000RPM 600W 960W
Cooling forced by air flow
Resistance to fuel, oil, water, mechanical stress
Operating temperature -30°C to 120°C