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RUNNING-IN ("Breaking-in)
For long life and high-performance, this engine needs to
be properly "run in", or "broken-in". The following settings
apply when using a fuel containing not less than 15%
lubricant and not more than 10% nitromethane.
Needle-valve setting for starting
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1
Open the needle-valve 1 turns from the fully closed
position. When using the optional fine-tapered needle
supplied with the engine, open the needle-valve
approx. 2 turns.
Bench or ground running
Preferably, use a propeller of slightly lower pitch than
the one intended for actual flight. Start the engine and
open the throttle. Close the needle-valve gradually and
allow the engine to run at its maximum r.p.m. for just
one or two seconds, then immediately reopen the
needle-valve a half-turn and run the engine with this
rich mixture for 5 to 6 seconds.
Repeat this procedure until the fuel tank is empty.
Idling adjustment
Start the engine with the needle-valve setting at the
original starting position. Close the needle-valve
gradually and set it at 1/8 to 1/4 turn opened from the
maximum r.p.m. position. Adjust the idling with this
needle-valve setting.
In-flight running-in
During the first 3 or 4 flights, try to avoid successive
nose-up manoeuvres. Since, during running-in, the
engine will tend to overheat, set the needle-valve
carefully so that the mixture is always slightly rich. If the
mixture becomes lean during a nose-up manoeuvre
such as a loop, land the model and open the needle-
valve 1/8 to 1/4 turn. If the engine becomes too rich
during level flight with this needle-valve setting, increase
the header pipe setting 10 to 20mm and re-set the
needle-valve. At least 10 flights are required for the
completion of running-in. Note that the engine will
develop its full performance only after running-in is
completed.
Model engines generate considerable heat.
Do not touch any part of your engine until it
has cooled. Contact with the muffler (silencer),
cylinder head or exhaust header pipe, in
particular, may result in a serious burn.
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2
1
Note:
It is important to be able to run the engine on a rich
mixture during the breaking-in period to avoid
overheating. If the fuel/air mixture does not become
sufficiently rich, even when the needle-valve is opened
more than 5 turns, first check that the carburetor has
not become clogged with dirt or fluff. Also check that
the fuel tubing has not become holed or split and that
the fuel pick-up weight is not sticking to the tank wall.
(See previous reference to 'FUEL TANK'.) If, at any
time, the engine cannot be persuaded to run rich after
checking the above, it is possible that a fault has
developed in the pump. In this case, consult the O.S.
engine distributor in your country.
As the running-in proceeds, a slightly different idling
mixture will be required for best carburetor performance.
Therefore, adjust the mixture control valve accordingly.
During the first few (running-in) flights, the engine may
sometimes stop because the carburetor adjustments have
yet to be finalized at this stage. Be prepared, therefore,
to make an emergency landing at this time.
MIXTURE CONTROL ADJUSTMENT
Before starting the engine, open the Needle-Valve 1
turns from the fully closed position.
(When the 10-20% nitro fuel is used)
Set the throttle very slightly open from the idle position
and start the engine in the usual way. It is preferable to
have the throttle only slightly open, to avoid
unnecessarily high revolutions when the engine starts.
Now open the throttle fully and gradually close the
Needle-Valve until the engine is running at its maximum
speed.
Do not close the Needle-Valve to too lean a setting, as
this will cause overheating which may result in internal
damage and reduced engine life. Set the Needle-Valve
approximately 3 to 4 clicks open (i.e."rich" ) from the
peak r.p.m. setting, even though this will slightly reduce
r.p.m. on the ground.
Make sure that the engine is fully "run-in" before
operating it continuously at full power.
Having set the Needle-Valve as described above, close
the throttle. The engine should idle steadily and
continuously. (If it stops immediately, first try turning the
Throttle Stop Screw clockwise a few degrees to raise
the idling speed a little.)
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Note:
If, however, the engine idles unevenly and smokes a
good deal when the throttle is re-opened, before picking
up speed, it is probable that the idling mixture is too rich.
In this case it will be necessary to turn the Mixture
Control Screw clockwise about 5 degrees.
Alternatively, if the Mixture Control Screw is set too
lean, the engine may stop when the throttle is closed, or
it may idle for a few moments, then speed up very
slightly before coming to a stop. Re-opening the throttle
under these conditions will usually result in the engine
cutting out abruptly, without smoking. Corrective action
is to turn the Mixture Control Screw about 5 derrees
counter-clockwise. out readjustments progressively and
patiently, remembering the symptoms of rich and lean
running, quoted above, until the engine responds
quickly and positively to the throttle.
Once the correct carburetor settings have been
established, it should be unnecessary to alter them.
Such slight readjustments may be necessary for
optimum performance if defferent types of fuel,
glowplugs or propellers used.
PD-06 FUEL PUMP - WARNING!
Never disassemble the pump
If the pump is dismantled, its
original performance may not be
restored.
Never move the screw on the pump
This is precisely adjusted at the factory. If the
screw is disturbed, it cannot be re-set at its
optimum position without using special measuring
instruments.
Any foreign matter entering the Pump System may
interfere with its correct functioning and may even
damage the pump diaphragm. Be sure to filter all fuel
before filling the tank and, most important, use a good
quality fine filter in the delivery tube between the tank
and pump.
Use fuel filters
Never attempt to "clean-out" the inlet and outlet
nipples with a sharp instrument, such as a pin or
thin wire.
This will damage the pump
and render it inoperative.
In case of a pumped engine, if the needle-valve is too
much opened, at acceleration mixture seems to be rich
even if idling mixture is lean. If the idling mixture is too
lean, the engine will stop with prolonged idling (more
than 30 seconds). In this case, adjust the mixture
control valve to richer side and close the needle-valve to
the appropriate point.
