Key facts
- Brand
- O.S. Engines
- Model
- 91HZ-R
- Industry
- Industrial
- Documents
- 3
- Languages
- EN
- Last added
- 2012-08-08
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O.S. 91HZ-R F3C Engine Instruction Manual
This document is the instruction manual for the O.S. 91HZ-R, a factory-tuned internal combustion engine developed expressly for F3C model helicopter flights. It features an integrated Demand Regulator System (DRS) to ensure steady fuel supply during vigorous attitude changes and includes a new 61F carburetor with twin needles for independent mixture adjustment.
Read onlineO.S. Engines 91HZ-R specifications
| Fuel Type Requirement | Helicopter use fuel with 10% to 30% nitromethane |
|---|---|
| Lubricant Requirement | At least 18% lubricant by volume |
| Glow Plug Type | O.S. No.8 |
All O.S. Engines 91HZ-R documents by type
Day-to-day operation, settings and troubleshooting. Start here if the product is already set up.
Questions answered in these manuals
What type of fuel is recommended for this engine?
A fuel containing 10% to 30% nitromethane is preferable for best throttle response.
What is the minimum lubricant requirement in the fuel?
The fuel must contain at least 18% lubricant by volume for consistent performance and long engine life.
What is this engine designed for?
This engine was designed specifically for model helicopters and should not be used for any other purpose.
How should the carburetor needles be adjusted?
The twin needles on the 61F carburetor allow for independent adjustment of the idling/hovering and high speed mixture.
What safety precautions are required when operating the engine?
Never operate the engine in an enclosed space due to carbon monoxide exhaust, and do not touch rotating parts or the hot muffler.
What type of fuel is recommended for the MAX-91HZ-R?
Fuel containing 10% to 30% nitromethane and at least 18% lubricant by volume is recommended for best performance.