22
Now disconnect the glowplug battery.
8.
Adjust the needle-valve
9.
Abrupt adjustment of the needle-valve may cause the
engine to stop, especially when it is new and insufficiently
run-in.
As the speed of the engine does not instantly change with
needle-valve readjustment, small movements, with pauses
between, are necessary to arrive at the optimum setting.
Practical best (optimum) needle-valve setting
Approx. 40
Maximum rpm setting
("Lean")
"Rich" needle-valbe
setting when starting
the engine.
Rpm starts to decrease.
Close the needle-valve
gradually and slowly.
Engine stops.
Re-starting the engine when warm
To re-start the engine when warm, simply re-energise the
plugs and reapply the starter with the throttle in the idling
position. If the engine does not start, disconnect the battery
from the glowplugs and re-prime. Initially, the high
temperature inside the combustion chambers may turn the
liquid fuel into gas and emit it through the exhaust pipes.
Therefore, repeat the priming procedure once or twice until the
cylinders become cool enough for restarting.
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.
How to stop the engine
Pull down the throttle lever and trim lever on the transmitter
fully.
23
RUNNING-IN ("Breaking-in")
Obtain an 18x12 or 20x8 propeller for running-in.
↓
↓
1
2
1. Running-in on the ground
Start the engine
Set the needle-valve 500-1,000r.p.m. lower than
maximum r.p.m. setting and run approx, 10 seconds.
(It is suggested to use a tachometer.)
Open the needle-valve approx. 1,000r.p.m. lower
than above setting and run approx. 20 seconds.
Repeat above procedure, i.e., richening and leaning the
mixture until the engine has approx. 10 minutes of running
time.
Keep the throttle fully open, using only the needle-valve to
change r.p.m. Prolonged running-in on the ground is not
suggested because the purpose is just initial running-in
to increace engine temperature gradually close to that of
maximam r.p.m.
NOTE:
2. Running-in in the air
Start the engine
Fly the model.
NOTE: Avoid prolonged heavy load flight.
With each successive flight, close the needle-valve slightly,
until, at the end of 10 flights, the needle-valve is set for
optimum position.
Finish running-in.
The carburetor can now be adjusted for optimum throttle
performance following the instructions given in the next
section.
Set the needle-valve approx 40 open from
optimum position (approx. 40 open from
maximum r.p.m.).
