This is the MXZ "Team Edition" engine with Airmax Filter from Ultimate Racing. The "Team Edition" concept uses the same Ultimate engines that are for sale, but the engines are assembled directly in our factory, completely broken-in and then thoroughly checked by our competition team to extract 100% of the performance of Ultimate engines.

There are many manufacturers that offer pre-break-in services performed on benches with propellers. The problem is that this method only works as a pre-break-in. It is still necessary to continue breaking in the engine on the track.

At Ultimate Racing we wanted to go a step further and offer our customers the possibility of purchasing fully broken-in and ready-to-race engines without the need for any additional break-in on track, i.e. engines that can be used in the most demanding competitions as you receive them, directly from the box.

To ensure quality and that all "Team Edition" engines are broken-in exactly the same, we have evolved a fully monitored break-in bench where temperature, RPM and break-in time are controlled at all times. The whole break-in process is performed with the engine perfectly lubricated to minimize the loads and wear of all the parts, significantly increasing its useful life.

During each of the break-in stages the engine's resistance torque is also controlled. Using this parameter, we know when the engine break-in is finished, ensuring that all of our "Team Edition" engines are perfectly broken-in and ready to compete.

Once the break-in process has completed, the engines are dismantled, checked piece by piece and assembled again by our competition team, thus ensuring the highest quality of product reaches our customers.

This engine is manufactured by the prestigious Japanese brand O.S. Engines, with the following characteristics:

Cooling Head

The MXZ is equipped with the same cooling head as its predecessors. This 8-fin cooling head has a very low center of gravity and has been designed to focus most of the airflow directly to the glow plug. By cooling the glow plug we get a more stable carburetion and idle.

Carburetor

Once again, the MXZ comes with the 21 J3 carburetor. Unlike the original OS carburetor, its high-speed needle holder was redesigned for better refrigeration of the fuel flow into the carburetor, lowering the temp of the carb, and consequently making it more stable with great idle stability, improved fuel mileage, and overall engine performance.

Besides this, the uniball joint of the carb slide was also modified with two stoppers instead of one. With this new modified design, you can easily adjust the angle of the uniball joint without having to disassemble the engine. This carb offers higher accuracy tuning, a very interesting advantage to experienced drivers.

Crankshaft

The MXZ comes with a 14mm crankshaft with a teardrop-shaped opening and paste in the inlet for improved flow.

Bearings

The MXZ comes with the original OS steel bearing in the rear and Ultimate Racing double-sealed steel in the front.

Venturi

The MXZ comes with the 6.5mm Ultimate Racing FLOWMAX venturi. With an innovative design, longer than the standard O.S. venturis and wider at the base, it ensures the inferior part of the venturi and the carburetor have exactly the same diameter. This new geometry improves fluid dynamics, providing extra power that allows the use of smaller venturis without decreasing power, and as a consequence, improves fuel mileage.

Sleeve and Piston

The sleeve with 3 inlet ports and an exhaust port guarantees low fuel consumption with very high but smooth and linear power. Both the sleeve and piston are made from a high-strength aluminum bar to improve durability.

Technical Specifications

Displacement: 3.49 cc

Bore: 16.27 mm

Stroke: 16.80 mm

Sleeve: 3 + 1 ports

Practical RPM range: 4,000 – 40,500 rpm

Max. power output: 2.55 hp at 34,000 rpm

Weight: 350 g

Crankshaft: 14 mm

Carburetor: 21 J3

Glow plug: P3 Turbo

Exhaust Position: Rear