Adjusting your stock 49cc Mitsubishi single adjustment
carburetor for engines with centrifugal clutch.
The trick is to get the engine to accept full throttle while setting
still (tire on the ground).
Run the engine until it is hot (five minutes or so) then shut it off.
Check for leaking fuel, this could be caused by a leaking diaphragm.
Fuel line connected properly clear line will return fuel to tank
Turn the air/fuel adjuster clockwise (slotted screw found on the
lower left side) until it stops turning. Do not force the adjusting
Next turn the adjuster counter clockwise 2 turns. The engine
should start but will not run properly because this is the lean rough
Start the engine and gun it, if it tries to stall turn the air/fuel
adjustment counter clockwise ½ turn.
Try gunning the scooter again, if there is no improvement turn
the adjustment clockwise one full turn.
Tweak the adjustment.
Set the air/fuel adjust to a position that the engine will not
stall under full throttle
Set the idle adjustment , just fast enough that the
engine will not stall when throttle is released. (Phillips, upper
adjustment near throttle body).
Turn the idle adjust clockwise to speed up or counterclockwise to
slow the engine.
FLUTTER: This setting will cause the engine flutter at high RPM, an
advanced timing key will ease flutter if you want smooth top end