MOTOR OS .12XZ SPEED SPEC II TUNED 11680

This is the O.S. 12XZ Speed Tuned Spec II Engine.

FEATURES:

• Special coating on crankshaft reduces friction and wear
• Tungsten weights for better balance at high RPM
• Machined aluminum outer head with holes drilled for lighter weight and better cooling
• Newly designed crankcase and liner port for increased torque at low to mid speed
• 12F(B) slide valve carburetor

INCLUDES:

• O.S. 12XZ(P) Speed Tuned Spec II Engine
• Carburetor
• 5.5mm Carb
• Reducer
• RP6 Turbo Glow Plug
• Exhaust Gasket
• two Dust Caps
• Instruction Manual

REQUIRES:

• Fuel: 10-30% nitro content, 20% recommended for break-in
• Exhaust System: Depending on vehicle
• Air cleaner assembly, glow starter and track equipment

SPECS:

• Displacement: 0.128cu in (2.0cc)
• Bore: 0.543" (13.8mm)
• Stroke: 0.55" (14.0mm)
• Practical RPM: 5,000 - 44,000
• Power Output: 1.75hp @ 35,000rpm
• Weight: 7.76oz (220g)
• Height from crankcase bottom to top of cylinder head: 3.54" (90mm)
• Height/crankshaft center to top of cylinder head: 3.01" (76.6mm)
• Width including mounting tabs: 1.53" (39mm)
• Width not including mounting tabs: 1" (25.4mm)
• Width between mounting holes same side: 0.43" (11mm)
• Width between mounting holes opposite side: 1.23" (31.4mm)
• Cylinder head diameter: 1.93" (49mm)
• Length of exposed crankshaft: 1.16" (29.5mm)
• Length from backplate to front bearing: 1.96" (50mm)
• Length from backplate to end of crankshaft: 3.1" (79.5mm)
• Internal thread size at end of crankshaft: 1/4-28

Carburetor Settings:

• Needle Valve, Approximately 2-1/2 turns open from fully closed
• Throttle Stop Screw, Approximately 1mm visible from carb throat
• Mixture Control Valve: Rotate until slotted head is flush with carburetor body
• (Make adjustments only in small increments. Refer to manual for full break-in and carburetor adjustment instructions)

COMMENTS:

• Some notes on Slide Valve and Rotary Carburetors:
• Rotary Carbs offer a larger response in the middle of the power band. This works well for off-road applications when throttle response must be varied.
• Slide Valve Carbs provide greater response at the beginning and end of the power band.
• This works well for on-road and racing applications for fast take-offs and high speed.