O.S.Speed 91HZ-R & Powertune Pipe Combo

Here at BK Hobbies, we've put this combo together. This is one the most proven, reliable and powerful setups on the market. It includes an O.S. Speed 91HZ-R engine and a Powertune muffler that was specifically designed to work with this engine.

OS Engine

Features:

• Lightweight, machined heat sink head
• Big-bore carburettors best-suited for the intended use (F3C or 3D)
• Best precision advanced exhaust cylinder timing (for F3C or 3D)
• Newly designed combustion chambers, shaped to match the big bore carburetors and advanced exhaust cylinder timing
• Lightweight, forged steel crankshaft counter weight to lower vibration for higher speeds
• Improved back plate shape, to accommodate Futaba's BPS-1 RPM Sensor and increase primary pressure for greater stability
• The cover plate has a cell to accept a sensor designed to install in the cover plate from Futaba GY701 / CGY750 Governor
  

Technical Specifications:

• Displacement: 14.95cc
• Bore: 27.7mm
• Stroke: 24.8mm
• Output: 3.6ps/15,500RPM
• Practical RPM Range: 2,000-16,500
• Weight: 603g
  

Package Includes:

• Engine Pack O.S. Speed Tuned .91HZ-R Helicopter Engine with Pump, 61G Carb
• #8 Glow Plug
• Check Valve
• Head Gasket 0.2mm
• OS Speed Decal and English Instruction Manual

Powertune Pipe

Features:

• The power of Hatori without the weight or complexity
• The lightest aftermarket muffler available for the OS Max 1.05 at 235 gms
• Header opening matches exhaust port size
• Includes mounting accessories
• Tested by pro pilots