Force 21R Race .21 Rear Exhaust Engine

The Force 21R Race .21 Rear Exhaust Engine (FORE-21R46) showcases precision casting, machining, anodising and laser etching, backed by race-bred two-stroke design. Delivering a practical operating range of 6,800–37,000 RPM and a quoted 2.5 PS, this high-efficiency 5-port unit is built for serious performance with tunability to match.

A deep-fin CNC cylinder head promotes effective heat dissipation, while the three-needle carburettor offers fine control across the throttle range. Supplied venturi options (7 mm and 7.5 mm) allow you to tailor airflow to track conditions, pairing with the rear exhaust layout for a focused racing setup.

Key Features

• Deep fin CNC cylinder head
• Three-needle carburettor
• 7 mm and 7.5 mm carb venturi
• 5 inlet ports
• 3 outlet ports
• CNC backplate

Technical Specifications

• Stroke: 16.60 mm
• Bore (cylinder): 16.34 mm
• Practical RPM: 6,800–37,000
• Horse Power (PS): 2.5
• Shipping Weight: 0.48 kg / 1.05 lbs
• Colour: Black
• Material: Aluminium

Designed For Performance

This Force engine combines a highly efficient 5-port architecture with a rear exhaust configuration to support strong top-end speed and responsive power delivery. The precision CNC head and backplate contribute to durability and cooling, while the three-needle carb enables confident tuning for varied circuit demands.

Attention to detail continues on the outside with a premium anodised and laser-etched finish that complements the engineered internals. Whether you are refining your setup for outright pace or looking for predictable, controllable response, the Force 21R Race provides a high-quality foundation for competitive running.