OS Motors .21XZ-B V2 ABC

Updated on Jun 16, 2026 12:01:07 AM

This is the O.S. 21XZ-B V2 ABC Engine with 22B2 Carburetor
for 1/8 scale Off-Road Buggy Racing.
****** Because of the expressed racing nature of this engine, ******
****** it is NOT covered by the O.S. 2 Year Warranty ******
****** per page 8 of manual. ******


FEATURES:
High performance crankshaft has silicone filled intake passage and
    Tungsten counterweights
Lightening holes in cylinder head reduce overall weight
22B2 single needle slide valve carburetor
ABC piston and liner construction "A"luminum piston fitted to a
    "B"rass cylinder liner that is "C"hrome plated
Optimized power band


INCLUDES:
O.S. 21XZ-B V2 Off-Road Engine with 22B2 Carburetor, Exhaust
    Gasket, P3 Turbo Ultra Hot Glow Plug, yellow 7mm Carb Reducer,
    Instruction Manual and two Dust Caps


REQUIRES:
Fuel: 10-30% nitro content, 20% recommended for break-in
Exhaust System: Depending on vehicle
Glow starter, fuel tubing and track equipment


SPECS:
Displacement: 0.213 cu in (3.49 cc)
Bore: .641" (16.27mm)
Stroke: .661" (16.8mm)
Practical RPM: 3,000-41,500
Power Output: 2.7 PS @ 34,000 RPM
Weight: 12.77oz (362g)
Distance Between Mounting Holes Same Side: 0.83" (21mm)
Distance Between Mounting Holes Opposite Side: 1.45" (37mm)
Height Bottom of Mounting Tabs/Top of Cylinder Head: 3.4" (86.5mm)
Width of Mounting Tabs: 1.8" (45mm)
Distance from Backplate to Front Bearing: 2.5" (64.5mm)
Distance from Center of Crankcase to Front Bearing: 1.7" (44mm)
Distance from Center of Crankcase to Backplate: 0.81" (20.5mm)


Carburetor Settings, NOTE carburetor is preset at factory and
requires very small adjustments
    Needle Valve: Gradually reduce factory needle valve setting in 15°
increments following instructions in manual
    Metering Needle: After setting at optimum position run vehicle in
straight line and turn metering needle clockwise 15-30° to lean
mixture, or 15-30° counter clockwise to richen mixture
    Throttle Stop Screw: Turn counterclockwise if engine runs too fast
with throttle closed




BOX DIMENSIONS: 4.75" W. X 3.88" H. X 6.25" L.
BOX WEIGHT: 1.10 LBS.