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With the optimum mixture control position,
light smoke is visible during high speed
running,and the engine revolutions increase
smoothly during acceleration. Remember
that, if the engine is operated with the fuel/air
mixture slightly too lean, it will overheat and
run unevenly. As with all engines, it is
advisable to set both needle-valve and
mixture control screw very slightly on the rich
side of the best rpm setting, as a safety
measure.
If the engine runs too fast with the throttle
closed, the throttle stop screw should be
turned counter-clockwise to allow the throttle
opening to be reduced.
Finally, beyond the nominal break-in period,
a slight readjustment toward a leaner needle
setting may be required to maintain
performance.
Warning!
Mixture adjustments (whether via the
Mixture Control Valve, or the Needle-Valve)
cannot be made accurately under 'no-load'
conditions, which, in any case, are not
advised, since such operation carries the
risk of seriously damaging the engine
through over-revving and overheating.
Carry out adjustments patiently, under actual
running conditions, until the engine responds
quickly and positively to the throttle control.
CARBURETOR CLEANLINESS
The correct functioning of the carburetor
depends on its small fuel orifices remaining
clear.
REALIGNMENT OF METERING NEEDLE AND
MIXTURE CONTROL VALVE
In the course of making carburetor adjust-
ments, it is just possible that the Metering Nee-
dle and the Mixture Control Valve may be inad-
vertently screwed in or out too far and thereby
moved beyond its effective adjustment range.
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Mixture Control Valve
Carburetor Body
Slide Valve
Carburetor Body
Metering Needle
Rotate the Metering
Needle until its slotted
head is flush with the
ball link body. This is the
standard position.
Ball Link
First rotate the Mixture
Control Valve until its slotted
head is flush with the
carburetor body. Then screw
the valve in exactly 0.5 turn.
This is the standard position.
The basic positions can be found by rotating
the Metering Needle until its slotted head is
flush with the ball link body.
Rotate the Mixture
Control Valve until its
slotted head is flush with
the ball link body. This is
the standard position.
Mixture Control Valve
Carburetor Body
Throttle Lever
In case of the 11K carburetor
In case of the 11L carburetor
