O.S. engine MAX-75AX-BE Instruction Manual page 14

When the engine is started, open the throttle
slowly and adjust for the maximum r.p.m.
With this needle-valve setting, the mixture is
fairly rich. Close the needle-valve gradually
until just short of the peak r.p.m. Disconnect
the plug leads and further close the needle-
valve to the optimum position.
Then, close the throttle to idle, and open
smoothly to maximum r.p.m.
increases smoothly to maximum r.p.m., the
needle setting is OK.
If not, the needle setting is still rich. Close the
needle-valve further (10~15 degrees at a
time), and check the maximum r.p.m. If the
needle-valve is closed too much, the engine
will not accelerate and the r.p.m. decrease or
the engine will stop.
Once the optimum needle-valve is set, there
will be no need to change the setting in the
same day unless atmospheric conditions
change a lot. The optimum setting may vary
slightly according to the temperature and
atmospheric conditions.
Note:
Readjustments are
propeller is changed even with a same size
of the same brand.
Note:
Until the engine warms up sufficiently, the
engine tends to stall or quit when the
throttle is opened before reaching the
maximum r.p.m. This is because the 75AX-
BE consumes much less fuel and the fuel is
not vaporized sufficiently.
It is necessary to warm the engine up well so
that the fuel may vaporize sufficiently in order
for the engine to run steadily at maximum
r.p.m. When the temperature is lower (below
10 C), it will take some time for the engine to
be warmed up. Adjust the needle-valve until
the engine is sufficiently warmed up and r.p.m.
changes smoothly in proportion with the throt-
tle opening and closing.
If the r.p.m.
Open the needle-valve 1/2~1 turn when
restarting the engine after the flight. Then, start
the engine and adjust the needle-valve after
warming the engine well up. (Longer warning
up time is required when the temperature is
low, while shorter warning up time is required
when the temperature is high.)
26
required when a
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The 75AX-BE requires some patience when
adjusting, so become acquainted with the
needle-valve setting procedure described
above.
How to stop the engine
Pull down the throttle lever and trim lever on
the transmitter fully.
Note:
Make sure that the throttle linkage is made
so that the throttle is fully closed when the
throttle lever as well as trim lever on the
transmitter are fully pulled down.
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