MXR V3 Ceramic Motor with Airmax Ultimate filter

This is the .21 Competition Engine with 3 transfers Ultimate MXR v3 Ceramic with Ultimate Airmax Air Filter. This engine is manufactured by the prestigious Japanese brand O.S. Engines and is also based on their Speed B21 square stroke engine.

In addition to the modifications that the previous version already had, such as the crankshaft, the rear crankcase cover, the engine group, the innovative 6 and 6.5mm FlowMax venturi, and the crankcase designed to achieve greater power without compromising fuel consumption, the v3 incorporates a new less sensitive high needle for easier tuning.

With this engine, you'll experience an incredible power curve that delivers spectacular usable power at all times. It provides linear and smooth power at low RPM, making it perform perfectly on bumpy tracks, while also delivering great power at mid and high RPM, with excellent feel. It is one of the engines with the best idle on the market.

Highlighted features:

Carburetor: Modified OS21J3 carburetor needle holder and high needle for more stable operation and more precise tuning.

Crankcase: Same as the v2, where the crankcase was worked on to improve the internal fuel flow, thus achieving extra power and efficiency.

Filter: All Ultimate MXR v3 include a complete Ultimate Airmax filter set.

Head: The Ultimate MXR v3 is equipped with the same head as its predecessor. This 8-fin head has a very low center of gravity and is designed to direct most of the airflow directly to the spark plug. By cooling the spark plug, we achieve more stable tuning and idle.

Venturi: The MXR incorporates the new 6.5mm FlowMax venturi. With an innovative design that is longer than standard O.S. venturis and wider at the base. The new geometry improves fluid dynamics, providing extra power and a notable improvement in engine autonomy.

Rear Cover: The usual red crankcase cover of Ultimate engines is made from a bar of Swiss 7075-T6 aluminum and incorporates two larger ducts that improve the engine's fuel flow, increasing power and improving consumption.

Liner and Piston: Starting from the solid base of the MXS, the Ultimate MXR has been developed with a new engine group where the transfers have been modified to vary the intake and exhaust timings, achieving more power without compromising consumption.

Bearings: The Ultimate MXR v2 uses the original O.S. ceramic rear bearing and a front bearing with steel balls and double cover from Ultimate Racing.

Technical specifications:

Displacement: 3.49 cc

R.P.M. (power): 2.65 PS @ 34,000rpm

Stroke: Square 16.40x16.40mm

Liner: 3 + 1 ports

Rear bearing: O.S Ceramic

Front bearing: Ultimate Racing Steel

Crankshaft: 14mm balanced with two tungsten bushings

Carburetor: O.S 21J3 Modified with exclusive needle holder

Spark Plug: P3 Turbo

Weight: 345g