This is the O.S. Max 21TM Engine with the Revo Manifold.  This is a direct fit for the Traxxas Revo 2.5 and 3.3 monster trucks.  The .21TM is designed to be used with either the EZ-Start system or the Traxxas pull-start without modification.  This engine comes with a two-year limited warranty.

Features:

• Adapts perfectly to the Traxxas E-Z Start or pull-start systems with no modifications
• Included manifold is specially designed to fit directly onto the Revo
• Traxxas' clutch assembly bolts right to the crankshaft with no modifications
• 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. LC3 glow plug suitable for off-road applications that require constantly varying speed

Includes: One O.S. Max 21TM Engine with Revo Manifold, LC3 glow plug, 11K slide valve carburetor, manifold spring, rubber exhaust gasket, sticker sheet and instruction manual

Specifications:
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 / 29,000 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)
Distance/bottom of mounting flanges/top of cylinder head:3.2"(81.2mm)
Width of mounting flanges:                             1.5" (39mm)
Length of exhaust flange:                              0.24" (6mm)
Height/backplate mount to top of cylinder head:        3.3" (85.3mm)