O.S. 21TM ABC w/2.5 & 3.3 T-Maxx Manifold .21 Engine

Tower Stock# OSMG2083  •  Manufacturer Stock# 12240
Notes from our tech department:
This is the O.S. Max 21TM Engine with T-Maxx Manifold.
Direct fit for the 2.5 and 3.3 Traxxas T-Maxx monster trucks.



Adapts perfectly to the Traxxas E-Z Start or pull-start systems with
no modifications
Included manifold is specially designed to fit directly into the
Traxxas clutch assembly bolts right to the crankshaft with no
Oversized cooling fins on crankcase helps to keep engine cooler
Three needle slide valve carburetor with fins to help cool the fuel
as it enters the engine
High-performance long reach O.S. glow plug suitable for off-road
applications that require constantly varying speed
Two year limited warranty


One O.S. Max 21TM Engine with T-Maxx Manifold, LC3 glow plug, 11K
slide valve carburetor, exhaust gasket, manifold spring and
instruction manual


Installing in vehicle
Air filter


Displacement: 0.21 cu in (3.4cc)
Bore: 0.669 (17mm)
Stroke: 0.590 (15mm)
Practical RPM: 3,000 - 35,000 RPM
Output: 1.8 PS, 1.77 HP29,000 RPM
Weight: 8.57oz (243g)

Distance between mounting hole centers same side: 0.43 (11mm)
Distance between mounting hole centers opposite side: 1.2 (31.4mm)
Distance from end of crankshaft to drive washer: 1.03 (26.3mm)
Distance from center of engine to front bearing: 1.4 (34.8mm)
Width of mounting flanges: 1.5 (39mm)
Length of exhaust flange: 0.24 (6mm)
Heightbackplate mount to top of cylinder head: 3.3 (85.3mm)


Needle Settings:
- High Speed Needle (Needle Valve) 2-12 turns out from close.
To break-in close approximately 30 after running one tank
of fuel through vehicle, repeat five times
- Mid Range Needle (Mixture Control Valve) Screw head is exactly
12 turn in from flush with the carb body
- Low Speed Needle (Metering Needle) Turn 30 clockwise to lean
mixture or counter-clockwise to richen mixture

jxs 83107



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