O.S. Max B21 Engine (Drake In Service Done) - OSMG2150

🏁 Engine Overview

The O.S. MAX-B21 is a versatile and affordable .21 engine designed for 1/8 Nitro Off-Road and 1/8 GT racing. With performance inspired by the O.S. SPEED line, the MAX-B21 delivers an ideal balance of smooth power, stability, and ease-of-use—perfect for entry-level racers, club racers, and competitive sports-class drivers.

The lightweight outer head is based on the MAX-21XR-B Ver.3 and has been further optimized to reduce mass while improving heat dissipation. The inner head features a redesigned combustion chamber for improved burn efficiency and noticeably better low-end throttle response—making the engine extremely easy to drive, tune, and maintain.

Idling stability is greatly improved, reducing the chance of flame-outs and making carburetor adjustments straightforward for racers of all skill levels. This engine also comes professionally broken-in with the EBIS system, giving you a clean and consistent starting point right out of the box.

Features:

• Perfect for 1/8 Off-Road Buggy, Truggy, and 1/8 GT
• Excellent cost-to-performance ratio for new & sports-class racers
• Based on proven O.S. SPEED engine technology
• Lightweight cooling head for improved performance
• Revised combustion chamber enhances low-end response
• Stable idle and low stall tendency for easy tuning
• Comes EBIS break-in ready for immediate track use

Includes:

• (1) O.S. MAX-B21 Engine
• (1) O.S. P3 Glow Plug
• (1) 6mm Carb Reducer (Orange)
• (1) 7mm Carb Reducer (Yellow)
• (1) Exhaust Seal Ring
• (1) Dust Cap Set (3mm / 16mm / 18mm)
• EBIS Professional Break-In

Part Number: OSMG2150