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11.3.3 Check
Check whether the needle valve assembly, needle valve seat and float assembly are abrasive or damaged.
Replace any abrasive or damaged needle valve core.
Replace the carburetor body if the needle valve seat
is abrasive.
Replace any abrasive float tongue.
Check whether the carburetor oil needle is
abrasive or damaged. If yes, replace it
and also the main jet.
Check whether the idle metering jet, main
metering jet and main jet are abrasive,
damaged or stained. If yes, replace it.
R
eplace any abrasive plunger.
Clean any stained carburetor or fuel pipes according
to instructions.
11.4 Installation and adjustment
Assemble or install it in reverse order.
Carburetor adjustment
Note:
the idle adjusting screw has been adjusted for the carburetor in factory, which needs no adjustment usually.
In disassembly, record the rotation number for installation.
Start and warm up for about 3 minutes to make the engine run at normal driving temperature.
Adjust the idle adjusting screw to make the engine run at 1800rpm;
Tighten the mixture adjusting screw to the extreme with moderate force;
Then the engine flames out (if not, check whether the air filter connecter is leaked, or screws are tightened or air
filter inlet is blocked);
Retreat the mixture adjusting screw by one circle;
Restart and adjust the idle adjusting screw to reach 2000-2500rpm;
Adjust the mixture adjusting screw (counter-clockwise) slowly until the engine reaches the maximum speed
Screw
Float chamber
Idle adjusting screw
Float pin
Needle valve assembly
Float
Main metering jet
Main foam pipe
Idling jet
