The Ultimate MXZ is a 3-transfer, long-stroke .21 off-road engine built by O.S. Engines. It is tuned for smooth, linear power and lower fuel consumption, making it a great choice for club and race drivers alike.
Team Edition: fully run in at the factory on a monitored bench (temperature, RPM and time), with resistance torque measured to decide when run-in is complete. The engine is then stripped, inspected and rebuilt by the Ultimate race team, so it is ready to race straight out of the box with no track run-in needed.
Features
- Built by O.S. Engines
- Smooth, linear power with low fuel consumption
- Laser-finished 8-fin cooling head
- O.S. 21J3 carburettor with cooled needle holder
- FlowMax 6.5mm venturi
- Ultimate Airmax air filter included
Specifications
- Displacement: 3.49cc (.21)
- Power: 2.55 hp @ 34,000 rpm
- Bore x stroke: 16.27 x 16.80mm (long stroke)
- Sleeve: 3 + 1 ports, aluminium
- RPM range: 4,000 – 40,500 rpm
- Crankshaft: 14mm
- Carburettor: O.S. 21J3 with cooled needle holder and adjustable barrel puller
- Venturi: FlowMax 6.5mm
- Glow plug: P3
- Exhaust: Rear
- Weight: 350g
In the box
- Ultimate MXZ .21 engine
- Ultimate Airmax air filter set
Needed to complete
- Glow plug (P3 recommended)
- Nitro fuel
- Clutch and flywheel to suit your car
- Exhaust pipe and manifold
Part number: UR3401-MXZX
