This is the O.S. 21XM Version II Air Cooled Outboard Marine Engine.

Because of the competition nature of this engine, it is NOT covered by the O.S. 2 Year Warranty.

Features:

• Designed expressly for small and medium size outboard boats
• Installed aluminum tilt transom mounting plate
• Preassembled outboard unit with flexible propeller
• Blue anodized aluminum heat sink head
• 42mm carbon fiber propeller
• 20J carburetor

Includes:

• O.S. 21XM Version II Outboard Marine Engine
• Muffler
• Mounting Plate
• #8 Glow Plug
• Propeller
• Outboard Unit
• Steering Arm and Instructions

Requirements:

• Glow Fuel: 10-30% nitromethane content, use 20% for break-in
• Glow plug igniter and shore equipment

Specifications:

• Displacement: .21 cu in (3.5cc)
• Bore: 0.654" (16.6mm)
• Stroke: 0.630" (16mm)
• Practical RPM: 3,000 - 25,000
• Power Output: 1.3 PS, 1.28 HP @ 25,000RPM
• Weight: 24oz (682g)
• Carburetor Settings:
• Needle Valve; 2.5 turns from fully closed
• Mixture Control Valve: Shoulder portion exactly at a tangent to
• the throttle rotor hole
• Distance between mounting hole centers same side: 0.98" (25mm)
• Distance between mounting hole centers opposite side: 1.5" (37.5mm)
• Distance/outer mounting hole centers on steering arm: 2.5" (64mm)
• Width of muffler: 1.8" (46mm)
• Distance from flywheel to skeg: 8.6" (219mm)
• Distance from mounting plate bottom to skeg: 3.4" (86mm)
• Distance from mounting plate top to flywheel: 3.5" (87mm)
• Distance from mounting plate to end of cavitation plate: 7.2" (183mm)
• Distance from mounting plate to prop attachment point: 5.9" (149.5mm)
• Distance from bottom of mount to driveshaft center: 1.3" (34.5mm)
• Height of mounting plate: 1.8" (46mm)

Comments:

This Engine STARTS AND RUNS IN A CLOCKWISE DIRECTION at the starter
cone. Any attempt to start engine in a counter-clockwise rotation
may cause serious damage to the engine. Because of the clockwise
rotation, the crankshaft has reverse threads.