UR3401-M3TX - M3T Ultimate Engine 3 Port Off Road Team Edition (Pre Run in)

(No reviews yet) Write a Review

M3T Ultimate Engine Team Edition - Pre Broken in, OS based engine

This is the 3 port .21 Off-Road Ultimate M3T Competition Engine. The Ultimate M3T is made by the prestigious Japanese O.S. brand and its based on their B2102 square stroke engine.

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.

The characteristics of this engine adds to the Ultimate line all the best possible features you can have on a nitro engine, specifically designed for maximum power, performance and tuneability. With this engine you will have a great and super smooth linear power from low to high R.P.M.


The cooling head has been redesigned by Modelix. Its not as low as the B2102 lower profile but its lighter so it keeps the centre of gravity as low as the B2102 but improving its performance on very high temperatures.


The Ultimate M3T engine comes with a new carburettor where high speed needle holder has been redesigned for a better refrigeration of the fuel flow into the carburettor, lowering the temp of the carb, and as a consequence its 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.


The backplate is CNC machined and made of 7075-T6 Swiss Aluminium. 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.


The M3T 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. Crankshaft durability has been improved thanks to the Diamond-Like Carbon (DLC) coatings.


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.


The engine is supplied with two venturis, a 6.0 and a 6.5 to adjust fuel mileage and torque.


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.

Displacement: 3,46 cc
Power Output: 2.65 PS/2.61 hp @ 34.000rpm
Practical Range RPM:  4.000-42.000
Bore x Stroke: 16,40x16,40
Sleeve: 3 + 1 ports 
Rear Ball Bearing: ceramic
Front Ball Bearing: steel
Crankshaft: 14 mm 
Carburetor: Aluminum w/ insulator gasket 
Glow plug: P3 Turbo
Exhaust Position: rear 
Weight:  345g
Fuel type: 25% nitro. Recommended fuel Nitrolux.