Protek Samurai 321B Instruction Manual page 15

marked places
• After the break in period, a leaner needle setting may be required to maintain maximum
performance.
C A R B U R E T O R C L E A N L I N E S S
The small fuel orifices must be kept clear to ensure correct carburetor function.
• REALIGNMENT OF THE LOW SPEED NEEDLE & MID NEEDLE
When making carburetor adjustments, it is possible that the low speed needle and mid
needle may be inadvertently screwed in or out too far and thereby moved beyond the
effective adjustment range. The basic positions can be found by rotating the low speed
needle until its slotted head is flush with the ball link body.
Carburetor Body
Ball Link
Low Speed Needle
Slide Valve
5.5 turns out. Make adjustments with the slide in the open position.
First rotate the mid needle until its slotted
head is ush with the carburetor body. This is the
standard position.
Close
Mid Needle
2¾ turns out. Make adjustments with the slide in the open position!
Carburetor Body
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Thermo Insulator
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
Rotate the low speed needle until the head
sticks out 0.5mm from the ball link body.
This is the standard position.
(Metering Needle)
G L O W P L U G
Since the chosen glow plug and fuel type will effect performance and reliability, it will
be worthwhile to test with different plugs to find the best plug for your application. We
recommend the ProTek R/C P3 plug. Carefully install the plug finger tight before final
tightening with the correct size plug wrench.
T H E R O L E O F T H E G L O W P L U G
With a glow plug engine, ignition is initiated when a 1.5 volt power source is connected to
the plug. When the engine is running and the power is disconnected, the heat retained within
the combustion chamber remains sufficient to keep the plug filament glowing. This keeps the
engine running. Ignition timing is automatic. This means under reduced load and higher RPM,
the plug gets hotter and fires the fuel/air charge earlier in the piston stroke; at reduced RPM
the plug becomes cooler and ignition is retarded firing the charge later in the stroke.
G L O W P L U G L I F E
In the case of high performance nitro engines, glow plugs must be regarded as expendable
items. However, plug life can be extended and engine performance maintained by careful
use, i.e.:
• Use a plug suitable for the engine.
• Use fuel containing a moderate percentage of nitromethane, unless more is essential for
racing events.
• Do not run the engine too lean and do not leave the igniter battery connected while making
needle adjustments.
W H E N T O R E P L A C E T H E G L O W P L U G
Apart from when actually burnt out, a plug may need to be replaced because it no longer
delivers its best performance, such as when:
• Filament surface is rough and has turned white.
• Filament coil has become distorted.
• Foreign matter has adhered to filament or plug body has corroded.
• Engine tends to cut out when idling.
• Engine becomes more difficult to start.
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