O.S. Engines 18TM Revo - Manual (Page 21)

Needle Valve
FINAL ADJUSTMENT
Final adjustment should be carried out only after
the running-in has been completed.
Throttle Stop Screw
Close
More fuel Less fuel
Metering Needle
Open
More fuel Less fuel
Needle Valve
Open
Metering Needle
Close
Run the vehicle (with throttle fully open) over
the longest available straight course, in order
to observe the model's speed. Next return
the car to the starting point, close the Needle-
Valve 30° and repeat the run, taking note of
the improvement in performance.
Continue with further runs, gradually
reducing the Needle-Valve setting and
aiming to achieve the highest straight-line
speed. Remember, however, that, if the
Needle-Valve is shut down too far, the
engine will overheat and, accompanied by
visibly diminished exhaust smoke, the model
will lose speed. At this point, throttle down
immediately, stop the vehicle and reopen the
Needle-Valve 45~90 degrees.
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