O.S. Pumper Engine Carburetor Adjustment Guide

About this manual

This guide provides procedures for setting the high-speed and idle mixture needles on specific O.S. pumped model airplane engines. It details how to select appropriate propellers based on target RPM ranges and explains the step-by-step process for leaning the engine at full throttle using a tachometer.

The document also covers troubleshooting steps if the engine fails to reach the specified RPM range, including considerations for altitude and fuel quality. Finally, it outlines the correct starting procedure after carburetor adjustment has been completed.

What's inside

• Applicable Engines
• Propeller Selection
• High-Speed Mixture Adjustment
• Idle Mixture Adjustment
• Starting Procedure
• Troubleshooting Low RPM
• Fuel Requirements

Frequently asked questions

What fuel type and nitro percentage are required for these engines?

You must use premium 2-stroke fuel containing either 10% or 15% Nitro.

What is the correct idle RPM range for FS-120 Surpass engines?

The idle speed should be between 2,400 and 2,600 RPM.

How long must the engine warm up before advancing to full throttle?

Allow the engine to warm up for about 30 seconds after starting.