The Ultimate MXR v3 Ceramic is a .21 square-stroke competition engine for 1/8 off-road, built by O.S. Engines on the Speed B21 platform. It delivers smooth low-end power for rough tracks, strong mid and top-end, and a reliable idle.
Features
- Built by O.S. Engines on the square-stroke Speed B21 platform
- New, less sensitive high-speed needle for easier tuning
- Revised crankcase internals for better fuel flow and efficiency
- Red CNC 7075-T6 aluminium backplate with larger fuel channels
- 8-fin low-CG cooling head that directs air to the glow plug
- Reworked sleeve and piston for more power without extra fuel use
- Ultimate Airmax air filter set included
Specifications
- Displacement: 3.49cc (.21)
- Power: 2.65 PS @ 34,000 rpm
- Bore x stroke: 16.40 x 16.40mm (square)
- Sleeve: 3 + 1 ports
- Crankshaft: 14mm, balanced with two tungsten weights
- Carburettor: Modified O.S. 21J3 with exclusive needle and needle holder
- Venturi: FlowMax 6.5mm
- Bearings: O.S. ceramic rear, Ultimate steel double-sealed front
- Glow plug: P3 Turbo
- Weight: 345g
In the box
- Ultimate MXR v3 Ceramic .21 engine
- Ultimate Airmax air filter set
Needed to complete
- Glow plug (O.S. P3 Turbo recommended)
- Nitro fuel
- Clutch and flywheel to suit your car
- Exhaust pipe and manifold
Part number: UR3401-MR3
