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h) Checking the Basic Carburettor Settings
Fine tuning of idle motion and full throttle can only be carried out with a well run-in engine.
The carburettor of the installed FORCE combustion engine is distinguished by a plastic and metal material combination. The low thermal absorption of the
plastic compared to a carburettor consisting entirely of metal reduces the premature evaporation of the fuel mixture in the carburettor.
This way, it is easier to adjust the fuel supply even if the engine is hot. Once a carburettor setting was selected, it remains reproducible and constant during
operation.
(1) Main nozzle needle (mix adjustment screw)
The main nozzle needle is located above the fuel supply to the carburettor. It is
adjusted for the first start of the engine and should not be modified yet.
The main nozzle needle regulates the air / fuel mix by full throttle.
Turn the screw clockwise to lean the mixture (reduce the fuel ratio) or anti-clockwise
to enrich the mixture (increase the fuel ratio).
The basic setting for the very first start should be selected in such a way that the
main nozzle needle is completely screwed in and then turned out by two to three
rotations.
(2) Throttle stop screw (idle speed-adjusting screw)
The throttle stop screw is the small screw next to the idle speed-mix adjusting screw.
It is already set and should not require any readjustment. The idle adjustment screw
regulates the position of the carburettor slide (the throttle stop) and thus the carbu-
rettor passage at idle speed.
We recommend a carburettor outlet of approximately 1.5 mm.
One clockwise turn of the adjustment screw increases the throughput; one counter-clockwise turn retracts the slider further and thus reduces the gap.
(3) Air intake opening
Here is where the air filter is mounted.
(4) Idle speed mix adjustment screw
The idle speed mix adjusting screw is the little screw on the side of carburettor linkage. It is adjusted for the first start and should not be modified yet. The idle
speed mix adjusting screw regulates the air/fuel mix when idle and in the transition interval to full throttle.
Turn the screw clockwise to make the mixture more lean (reduce the fuel ratio) or anti-clockwise to enrich the mixture (increase the fuel ratio).
Slight adjustment may be necessary later on depending on the fuel, glow plug and ambient conditions.
In order to reset the factory setting, proceed as follows:
• Open the carburettor slide completely
• Keep the slide open and turn the idle speed mix adjusting screw clockwise until it stops.
• Now unscrew turning it by 7.5 rotations anticlockwise.
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