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UAV systems for your project.


For the most optimal requirements, our plug &play  systems are fully compatible, it is up to you what you prefer.



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

Maximal power dissipation:20W

Nominal power (60 min):2200W

Nominal current (60 min):51A

Maximal power dissipation:10W

Nominal power (60 min):1500W

Nominal current (60 min):35A


Company Rotomotor ltd. developed based on customer requirements Hybrid power generators for Roto UAV engines.

Rotomotor Ltd supplies these generators under the trademark „STG Roto“ 500W, 1200W and 2500W.

All types are designed for maximum performance and efficiency. STG Roto start generators cooperate exclusively with the E-Control control unit, the main advantage is switching functions from the el. energy to the possibility of remote starting of the Roto combustion engine.

+ Remote start & stop

+ Hybrid system

+ Hybrid boost

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

  • ​E-Control enables remote start & stop of the Roto engine in flight,

  • Hybrid connection of both internal combustion engine & generator systems and thus obtaining combined power (Hybrid system).


Controller Roto

Roto controller are developed for the distribution of stabilized voltage in the range from 3.5VDC - 50.0 VDC and current outputs up to 25 A.

  • ​The outputs can be two and are fully stabilized at 300-2000W.

  • It can be used for direct power supply of on-board systems or batteries.

For all Roto four-stroke engines, a 300W-4000W power generator has been developed with Roto regulators that can provide a stabilized voltage of 3.3V-60V. These generators do not have the ability to remotely start the internal combustion engine. Their advantage is that they provide high power in a stabilized voltage energy suitable for direct power consumption on board your project.

+ Stabilized voltage

+ High power




Main unit, Injectors, Fuel pump, Fuel filter, Main cable connector, Fuel pressure sencor, Outsite temperature sencor, CHT sensor

For basic EFI configuration operation


Main unit, Injectors, Fuel pump, Fuel filter, Main cable connector, Fuel pressure sencor, Outsite temperature sencor, CHT sensor, Flight control display, wideband oxygen sensor controller & wideband oxygen sensor, Fuel level sensor

For advanced EFI configuration operation


The Control Module serves for the Engine Management setting without using a computer.

Recommended for first buy.


For easier connection of the EFI, it is possible to choose wired option.

EFI will be ready for use.


Exhaust gas temperature sensor.


The big advantage of Electronic Fuel Injection is the possibility to achieve very low fuel consumption. EFI installed on a Roto 125 FS engine achieves fuel savings of up to 40% compared to a carbureted engine.

The economic cost of an EFI Roto is higher than a carbureted engine, but if your project reaches series production the purchase price of the EFI will drop significantly due to the use of EFI LIGHT / Production. With the production version it is assumed that equipment such as Lambda probes, temperature sensors and adjustment modules will no longer be required for the EFI setup.

 At the time of series production, the economic costs will be offset by the lower price of EFI Light and the low fuel consumption.

 Another major advantage is the flight levels above 5000 meters above sea level.

+ low fuel consumption

+ Electronic control

+ flight level 5000 m.a.s.l.


The carburetor is a very good and inexpensive option for projects flying at flight levels below 2000 meters above sea level.

For missions lasting up to 5 hours, the carburetor is a good choice for both project cost and fuel economy.

The carburetor can be set up directly for your project, where we at Roto Motor Ltd will preset the PWM values for your mission and determine the best conditions for your engineers to control the throttle of the carburetor, in PWM values.

By maintaining basic parameters such as CHT and EGT temperatures, you can count on reliable and inexpensive operation of ROTO four-stroke engines.

+ Low purchase price

+ Simple control


Electric systems


Suitable for UAV projects within the range of 4 meters and weight up to 25 kg.


Suitable for UAV projects within the range of 4 meters and weight up to 35 kg.


Suitable for UAV projects within the range of 4,5 meters and weight up to 40 kg.


Suitable for UAV projects within the range of 5 meters and weight up to 45 kg.

Fuel systems

Roto engines are tested in harsh conditions simulating real missions from takeoff through the flight phase to the landing sequence.

We know that the engines are operated in harsh conditions with dusty environments, but also in rain and cold weather. We have tested all these conditions over the last 10 years on our Roto engines. Based on this experience, we strive to reach 300 hours TBO.

In every cooperation with the customer we try to get feedback from flight tests, based on which we can achieve TBO with a great range.

ROTO engines are designed based on many years of experience with a focus on high combustion engine life, long TBO and reliability.

Roto Motor Ltd. Czech Republic is the market leader in the market of internal combustion engines for UAV projects.

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