OS Engines

This is the B21 Adam Drake Edition 4 .21 off-road racing engine with the TB02 EFRA2089 tuned silencer and MB01-75 exhaust manifold combo set from OS Speed.


The B21 Adam Drake Edition 4 is O.S. Speed's latest collaboration engine with O.S. team driver Adam Drake. The cylinder liner, crankshaft and outer head have been redesigned to his specification for better balance, more torque and more power. This combo set adds the TB02 EFRA2089 tuned silencer and MB01-75 exhaust manifold.

Key Features:

• .21 (3.49cc) O.S. Speed B21 off-road racing engine
• Developed and tested with O.S. team driver and ROAR champion Adam Drake
• Newly designed 3-port cylinder liner with revised exhaust dimensions
• Revised crankshaft inner diameter
• Double anodised black and blue outer head with a new laser design
• Redesigned inner head combustion chamber
• Blue anodised 6II and 8mm carburettor reducers
• Supplied with the TB02 EFRA2089 tuned silencer and MB01-75 exhaust manifold

Package includes:

• 1x O.S. Speed B21 Adam Drake Edition 4 .21 Engine
• 1x TB02 EFRA2089 Tuned Silencer
• 1x MB01-75 Exhaust Manifold
• 1x O.S. Speed P3 Glow Plug
• 1x Carburettor Reducer 6II (Blue, Aluminium)
• 1x Carburettor Reducer 8mm (Blue, Aluminium)
• Exhaust Seal Ring
• 3x Dust Caps (3mm, 16mm, 18mm)

Required for Operation (Not Included)

• Glow fuel for model two-stroke engines
• Glowplug igniter
• Starter box
• Fuel filter
• Fuel pump or squeeze bottle

Technical Specifications:

This is the B2105 Engine With TB02 EFRA2089 and MB01-75 Pipe Combo set from OS Speed Including a P3 Glow plug, Reducer 6II and 6.5II (red)Al, Exhaust seal ring, and Dust cap set 3mm/16mm/18mm.

O.S.SPEED's off-road racing engine has further evolved. The B2105, which has evolved into the fifth generation of the B21 series, is designed to secure power that gives an advantage in harsh off-road racing scenes, and pursues a driving feel that steadily demonstrates performance in any situation. By re-designing the cylinder liner and crankshaft, we have achieved smooth and linear power delivery.
Furthermore, the effect of a lighter outer head successfully improves drivability in any situation.

Key Features:

• Factory tuned .21 (3.49cc) engine for 1/8 off-road competition
• Fifth generation of the O.S. Speed B21 series
• Newly designed 3-port cylinder and liner
• DLC-coated crankshaft
• Lighter outer head
• Crankcase from the B2104, with a ceramic rear bearing
• Specially treated thrust plate on the cover plate
• Supplied with the TB02 EFRA2089 tuned silencer and MB01-75 exhaust manifold

Package includes:

• (1) O.S. Speed B2105 .21 Engine
• (1) TB02 EFRA2089 (T-2090) Tuned Silencer Assembly
• (1) MB01-75 (M2000SC) Exhaust Manifold Assembly
• (3) Silencer Joint Springs
• (2) Exhaust Header Pipe Springs
• Exhaust Seal Rings
• (1) O.S. T-Series P3 Turbo Glow Plug
• (1) Carburettor Reducer 6II (Red, Aluminium)
• (1) Carburettor Reducer 6.5II (Red, Aluminium)
• (3) Dust Caps (3mm, 16mm, 18mm)

Required for Operation (Not Included)

• Glow fuel for model two-stroke engines
• Glowplug igniter
• Starter box
• Fuel filter
• Fuel pump or squeeze bottle

Note:  O.S. advise that after a major working part such as the piston and cylinder liner assembly is replaced, the complete running-in procedure should be repeated.

Key Features:

• Genuine O.S. Speed replacement top end for the B2105
• Part 4 in the O.S. Speed B2105 engine parts list (Built-up Parts Set C&P)
• B2105 3-port cylinder liner
• Supplied assembled

What's In The Box?

• 1x Cylinder and Piston Assembly (2EK03000)
• 1x Piston Pin (22016000)
• 2x Piston Pin Retainers (2AP17000)
• 1x Connecting Rod (22425003)

Technical Specifications:

This is the O.S. Speed TB02 EFRA2089 complete set from O.S. Engines which includes the TB02 tuned silencer and MB01-75 exhaust header pipe.

Key Features:

• EFRA homologated, EFRA number 2089
• Complete set: tuned silencer and exhaust header pipe
• The silencer and header pipe O.S. supply in the B2105 and B21 Adam Drake Edition 4 combo sets

Package includes:

• 1x TB02 EFRA2089 (T-2090SC) Tuned Silencer Assembly (72106190)
• 1x MB01-75 (M2000SC) Exhaust Header Pipe Assembly (72106440)
• 2x Long Mounting springs
• 3x Short Manifold springs
• 2x Exhaust seal rings

This is a P3 "Ultra Hot" Turbo Glow Plug from OS Engines.

This is a P4 "Super Hot" Turbo Glow Plug from OS Engines.

This is a P7 "Medium" Turbo Glow Plug from OS Engines.