Translations:KAVAN FS400AR - Instruction manual/34/en

Adjusting the Idle Mixture Control Screw

The special carburettor fitted to the FS 400 controls the amount of fuel entering the engine according to the throttle opening and thus, maintains the correct mixture strength at all speeds from idle to full power. As previously explained, the idle mixture control screw is set at the factory, but should be rechecked after proper break-in:

1. Start the engine, allow it to warm up, and then close the throttle. Allow engine to idle for a few moments and then reopen the throttle for full power. If engine performs well, move to Flight Section. If engine hesitates, move to Step A, B, or C.

Note: Any adjustments to engine should be done after engine is shut off.

1. If the engine hesitates at this point, while emitting an amount of smoke before acceleration, the setting is too rich. If the setting is too rich, turn the Idle Mixture Control Screw clockwise to lessen the mixture. About 1/12 (30 degrees) turn should correct the mixture setting.
2. If the engine stops or is slow to pick up speed, without smoking, it is probable that the idling mixture is too lean. In this case, it will be necessary to turn the Mixture Control screw counter clockwise, approximately 1/ 12 (30 degrees) turn should correct the mixture setting.
3. If the revolutions increase but the engine still appears sluggish, it is possible that one of the cylinders has stopped firing. This can be detected by checking for exhaust from all pipes. The cease firing of the cylinder may be caused by the idling speed being set ton low or the idling mixture either being too rich or too lean.
• Normal safe idling speeds are in the 2,000-2,200 RPM range.
• If the idle speed is set too low, reset the idle at a higher RPM using the throttle trim on the transmitter.
• If the idle mixture is too rich, turn the Idle Mixture Control Screw clockwise
approximately 1/12 (30 degrees) turn should correct the mixture setting.
• If the idle mixture is too lean, turn the Idle Mixture Control Screw counterclockwise approximately 1/12 (30 degrees) turn to correct the mixture setting.

Note: Please note that a 5 cylinder, 4 cycle engine may appear to have a higher idling RPM than actual. It is strongly recommended to always use a tachometer when determining actual idling RPM.

Note: Readjustment of the carburettor may be necessary whenever a change of glow plug or fuel is made.