This is the 3 port .21 Off-Road Ultimate MTS Ceramic Competition Engine. Made by the prestigious Japanese O.S. Engines brand and based on their long stroke Spec II configuration, the MTS features a DLC coated crankshaft with two balanced tungsten, modified backplate, and 21J3 carburetor to improve performance. The MTS is a great choice for use in nitro buggy and truck applications.  This engine provides amazing power and great fuel consumption. It has exceptional low to mid-range torque and a great idling.

COOLING HEAD
The cooling head has been redesigned by Modelix. It’s a low profile and light cooling head that keeps a lower center of gravity improving its performance on high temperatures.
 
CARBURETOR
The MTS comes with the 21 J3 carburetor. Compared to the original OS 21 J3 carb, its high-speed needle holder was 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 was also 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 MTS backplate has been modified. The backplate is CNC machined and made of 7075-T6 Swiss Aluminum. It’s been milled to improve the gas flow going to the piston 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 of the MTS is an evolution of the DLC B2102 but with two balanced tungsten in order
to increase the inertia to rotation.
 
BEARINGS
The MTS comes with the original OS Ceramic bearing in the rear and steel in the front.
 
VENTURIS
The engine is supplied with a 6.5mm aluminum 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 aluminum bar to improve its durability.

 
PIPE AND HEADER
This is the Ultimate Racing Super Strong EFRA 2141 exhaust system. This EFRA 2141 hi-quality aluminum exhaust has been designed to improve the overall performance of your engine. It produces a precise and linear throttle response in the low to mid RPM range with a great top end speed. This pipe set will provide great power to your engine up to the high RPM range to produce a great and easy to drive power curve. All these characteristics will provide great torque for those very demanding tracks with sharp corners and hard to clear jumps. This EFRA 2141 exhaust system is a great choice for your 1:8 off road engine, and it’s specially recommended for the M3R, M3X, M4R and M5 Ultimate engines This exhaust system includes the pipe, the manifold, 3 short springs, 2 medium springs, 1 long spring and 2 manifold gaskets.

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: 16,27x16,80mm
Sleeve: 3 + 1 ports
Rear Ball Bearing: ceramic
Front Ball Bearing: steel
Crankshaft: 14 mm
Carburetor: 21 J3
Glow plug: P3 Turbo
Exhaust Position: rear
Fuel type: 25% nitro. Recommended fuel Nitrolux.