O.S. Engines 18TM Revo - Manual (Page 12)

CARBURETOR CONTROLS
Four adjustable controls are provided on
this carburetor.
Needle Valve
Throttle Stop
Screw
Mixture Control Valve
Thermo Insulator
Metering Needle
The Needle-Valve;
For adjusting the mixture strength when the
throttle is fully open.
The Mixture Control Valve:
For changing the mixture strength at mid
speed and acceleration. (Do not rotate the
screw more than one turn.)
The Metering Needle:
For adjusting the mixture strength at part-
throttle and idling speeds, to obtain steady
idling and smooth acceleration to mid
speeds.
The Throttle Stop Screw:
For setting the minimum idle speed:
NOTE: Readjustment may be necessary,
occasionally to allow for changes in fuel
formula gear ratio or clutch engagement
point.
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