Rotomotor Roto Motor Gas Engines


Here you will find our Rotomotor Roto Motor Gas Engines.

Troy Built Models, Inc. is proud to announce our new partnership with Rotomotor!

Rotomotor is located in the city of Hronov in the Czech Republic. Using top of the line CNC equipment, they manufacture two and four stroke gasoline engines specifically designed for model aircraft use. The end result is a product of exceptional quality. The factory warranty period of 40 months speaks very confidently to the  extreme quality and reliability of their products.

These are some typical component manufacturing techniques used:

  • Crankcase – Rough castings are precision CNC machined and then painted.
  • Cylinder – CNC machined from high grade aluminum billet. The cylinder liner is made from granular cast iron, then sized and honed to an exacting tolerance, then pressed into place. 
  • Piston – Cast from high grade aluminum/silicon alloy and then precisely machined. A single piston ring is used. Wrist pin diameter is 8mm. 
  • Connecting rod – The aluminum forging is precisely machined and utilizes two needle bearings. 
  • Crankshaft – Made from solid steel, it is then hardened and ground to exacting tolerances.
  • Crankcase backplate assemblies  – CNC machined aluminum castings using either precision ground rotary valves for 2 cycle engines or a precision machined and hardened gear train and cam sets for 4 cycle engines.

Designing the engines from a “clean sheet” of paper allows the Rotomotor engineers to develop more sensible, efficient and compact designs.
This is especially true with the new 35FS single and 85FS opposed twin four stroke engine designs.
There is an inherent beauty and mechanical simplicity about these engines that is very appealing.
The goal for the new 35FS and 85FS four stroke engines was simple. They must be easy to start, develop very good power, be fuel efficient, operate quietly and be extremely reliable.

Troy Built Models has selected the Rotomotor 35FS and the 85FS four stroke engines to introduce customers to the Rotomotor experience. We feel very confident you will agree these are the finest four stroke gasoline model aircraft engines available.

TBM will be the service support center for Rotomotor engines.  
Rotomotor warranty is 40 months.
We will supply warranty support through Rotomotor with their approval pending pics of failures and serial #’s as we do now for other engines.
For all warranty related service issues, the customer is responsible for all shipping charges to and from Troy Built Models.




Allied countries of the United States regarding shipment of any products from TBM

WARNING - Gasoline and Turbine powered R/C model aircraft are not manufactured to withstand unlimited G's. Any R/C model aircraft can fail, be it a wing folding up or a fuselage breaking in half under too high of a load. Just as any full size aircraft, model R/C aircraft have a maximum G rating. Because you are not in the plane flying it and experiencing the G's and reading the G-meter, it is more difficult to judge the G's on the aircraft, and it is very easy to exceed the limits of the aircraft. Understand that if you perform a snap roll, parachute, wall, blender, knife edge loop, or pull hard on the elevator at almost any speed, you can be putting in excess of 15 G's, even in excess of 30 G's, and most aircraft can only designed to take 10-12 G's. If you perform any violent maneuver, you can break your plane. When I perform hard maneuvers, especially for the first time on an airframe, I am prepared for a failure and am prepared for it as best I can be. This mainly includes performing the maneuver far enough away from spectators that in event of a failure that I am not endangering others. In addition, be prepared for the manufacturer to not pay for a new airframe which is broken during flight. It is common practice for any manufacturer to not replace an airframe which breaks in the air or upon landing. I have only seen manufacturers replace airframes when they have received many of the same failures and the manufacturer determines that there was a design or manufacturing error. If you break an airframe, and you are the only one to do so, then it is probably not the fault of the manufacturer. Please fly safely, and avoid full throttle operation other than at low airspeeds.

R/C model jets, warbirds, aerobatic planes, DJI S1000 Octocopter, and UAV Unmanned Aerial Vehicles to name a few are not a toy! If misused, it can cause serious bodily harm and property damage. Fly only in open areas, and AMA (Academy of Model Aeronautics) approved flying sites. Follow all manufacturer instructions included with your plane, radio, servo's, batteries and engine. Aircraft manufacturers guarantees each kit to be free from defects in both material and workmanship at the date of purchase. This warranty does not cover any component assembled by the customer. All parts of high stress must be inspected and reinforced if necessary by a competent builder. Some parts should be glued again. High stress areas such as firewalls, motor boxes, wing mounts, landing gear mounts, etc., are areas of high concern. Seek help if necessary. In not case shall TBM be liable for the cost of any product it offers which is not manufactured by TBM. The liability to the manufacturer cannot exceed the original cost of the purchased item. Further, TBM reserves the right to change or modify this warranty without notice. In that TBM has no control over the final assembly or materials used for final assembly, no liability shall be assumed nor accepted for any damage resulting from the use by the user of the final user-assembled product. By the act of using the user assembled product, the user accepts all resulting liability. The kit manufacturers have provided you with a top quality, thoroughly tested kit and instructions, but ultimately the quality and fly ability of your finished model depends on how you build it; therefore, we cannot in any way guarantee the performance of your completed model, and no representations are expressed or implied as to the performance or safety of your completed model. It is the user's responsibility to inspect each component for worthiness.