This is the 3 port .21 Off-Road Ultimate M3X V2.0 Competition Engine. Like its predecessor M3X, the V2.0 is made by the prestigious Japanese O.S. Engines brand and it's based on their square stroke Speed B21 Ty Tessmann II edition engine.

Like the M3X, the M3X V2.0 it’s been specifically designed for maximum power, performance and tune-ability. With this engine you will have a great and super smooth linear power from low to high R.P.M.

The carburetor, crankcase and crankshaft have been developed to improve fuel consumption.

COOLING HEAD

The cooling head has been redesigned by Modelix. It’s not as low as the B2102 lower profile but it’s lighter so it keeps the center of gravity as low as the B2102 but improving its performance on very high temperatures. It’s the same head as the M3T and M3S engines.

CARBURETOR

Unlike the previous M3X, the V2.0 comes with the 21 J3 carburetor. Its high-speed needle holder has been redesigned for a better refrigeration of the fuel flow into the carburetor, lowering the temp of the carb, and consequently it’s more stable with a great idle stability, improves fuel mileage and overall engine performance.

Besides this, the uniball joint of the carb slide has also been modified with two stoppers instead of one. With this new modified design, you can easier adjust the angle of the uniball joint without having to disassemble the engine.

This carb offers a higher accuracy tuning, a very interesting advantage to experienced drivers.

BACKPLATE

The original design of the OS backplate has been modified. It’s been milled to improve the gas flow going to the piston.

The backplate is CNC machined and made of 7075-T6 Swiss Aluminum. The reason of making it with this material is to make it harder than the original and reduce the conrod-backplate friction increasing the life of the conrod and improving engine efficiency and performance.

Thanks to its design, you can remove the backplate without damaging the conrod even when it is on its lower position (PMI). The lateral grooves allow to easily remove the backplate without having to use any tool that can damage it.

CRANKSHAFT

The crankshaft selected for this V2.0 version is the B2101 one to increase the power at low RPM. This crankshaft has been designed by the O.S team of engineers to ensure an optimum flow of fuel thanks to the aerodynamic design and the silicone filling. It is balanced with a tungsten weight in order to increase the inertia to rotation.

BEARINGS

In line with the high quality and performance of this engine, its two high precision made in Japan bearings ensure high idle stability, longer life and low friction at high temperatures.

VENTURIS

The engine is supplied with a 6.5mm aluminium venturi.

SLEEVE AND PISTON

The sleeve with 3 inlet port and an exhaust port guarantee a low fuel consumption with a very high but smooth and linear power.

Both, the sleeve and piston are made from a high strength aluminium bar to improve its durability.

TECHNICAL SPECIFICATIONS

Displacement: 3,49 cc

Power Output: 2.61 hp @ 34,000 rpm     

Practical Range RPM:  4,000 - 42,000 rpm

Bore x Stroke: 16,40x16,40mm

Sleeve: 3 + 1 ports

Rear Ball Bearing: steel

Front Ball Bearing: steel

Crankshaft: 14 mm

Carburetor: 21 J3

Glow plug: P3 Turbo

Exhaust Position: rear

Fuel type: 25% nitro. Recommended fuel Nitrolux.