Pro Boat PRB09003 - Manual (Page 12)

48
Carburetor Factory Settings
The engine can be tuned from the factory settings to
optimize performance under various conditions. If you
lose track of the engine settings, return to these factory
carburetor settings.
Adjusting the High Speed Needle
If the top speed is slow, turn in the high-speed needle
1/16 turn and test. Do not exceed 1/4 turn in from factory
setting (minimum 1 1/4 turn out from closed) or the
engine will be damaged.
Adjusting the Low Speed Needle
If the vehicle accelerates slowly, turn in the low-speed
needle 1/16 turn and test.
Do not exceed 1/4 turn in from the factory setting
(minimum 1 turn out from closed) or the engine will be
damaged.
Idle Adjustment
RPM Lower (Arrow to left)
RPM Higher (Arrow to right)
If the idle is set too high (propeller turns) or too low
(engine does not stay running), adjust the idle speed on
the carburetor.
Engine Tuning
Before making adjustments:
• Ensure there are no leaks or obstructions in the
fuel tank, fuel tubing or the carburetor. Any faults
can affect engine operation and tuning.
• The carburetor needle is very sensitive. Adjusting
the needle even 1/16 of a turn is a significant
change. Be careful when making adjustments.
High-Speed Needle (on
the left side). Close the
high-speed needle by
turning it clockwise until
it stops, then turn it
counterclockwise 1 1/2
turns out (open).
Low-Speed Needle
(on the right side).
Close the low-speed
needle by turning
it clockwise until it
stops, then turn it
counterclockwise 1
1/4 turns out (open).
Idle Screw (below the needles).
Center the screw so the slot is
straight up and down.
1/16
1/16
Max 1/4
Max 1/4
RPM
Lower
RPM
Higher
12
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