Carburetor Cleanliness - O.S. engine max-18tz series Owner's Instruction Manual

Carry out adjustments patiently, under actual
running conditions, until the engine responds
quickly and positively to the throttle control.
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.
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.
The basic positions can be found by rotating
the Metering Needle until its slotted head is
flush with the ball link body.
In case of the 11K carburetor
Ball Link
Carburetor Body
Rotate
Needle until its slotted
head is flush with the
ball link body. This is the
standard position.
Metering Needle
Slide Valve
First
Control Valve until its slotted
head
carburetor body. Then screw
the valve in exactly 0.5 turn.
This is the standard position.
Mixture Control Valve
Carburetor Body

CARBURETOR CLEANLINESS

The correct functioning of the carburetor
depends on its small fuel orifices remaining
clear.
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.
22
the Metering
rotate the Mixture
is flush with the
23
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.
REALIGNMENT OF METERING NEEDLE AND
MIXTURE CONTROL VALVE
In case of the 11L carburetor
Rotate
Throttle Lever
Control Valve until its
slotted head is flush with
the ball link body. This is
the standard position.
Mixture Control Valve
Carburetor Body
the Mixture