Like its predecessor M3X, the MXS 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 but has some modifications on the crankshaft as well as on the back plate to improve performance. This engine has more power and returns to idle way better than its predecessor.
With this engine you will have a really good power band with a ton of usable power. It has a smooth bottom end which worked well on the bumpy track and then has a lot of mid-range pop and feel to it. It is one of the best idling engines you can find on the market.
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 high temperatures.
Unlike the previous M3X, the MXS 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.
The MXS 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.
The crankshaft of the MXS is an evolution of the DLC B2102 but with two balanced tungsten in order to increase the inertia to rotation.
The MXS comes with the original OS Ceramic bearing in the rear and steel in the front.
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.
Displacement: 3,49 cc
Power Output: 2.61 hp @ 34,000 rpm
Practical Range RPM: 4,000 – 42,000 rpm
Bore x Stroke: 16,40×16,40mm
Sleeve: 3 + 1 ports
Rear Ball Bearing: ceramic
Front Ball Bearing: steel
Crankshaft: 14 mm
Carburetor: 21 J3
Glow plug: P3 Turbo