Fuel System
4-8
4st 9.9/15/20 2008
a - Air intake
b - Float chamber inlet
c - Air-bleed inlet
d - Slow air jet
e - Bypass port
f - Main nozzle
g - Main jet
h - Slow jet
i - Air bleed hole
As throttle valve is turned to a position over bypass port, the vacuum produced in the back of throttle valve extends to an area
near main nozzle. At the same time, as flow of air that runs through carburetor bore increase, the whole space in the venturi
becomes vacuous. The vacuous pressure in this venturi causes large suction force in the main nozzle. The fuel goes through
main jet, flows into main fuel well, goes through main nozzle, and ejects from venturi.
The fuel that runs through main nozzle is mixed with air that comes from air bleed hole made on the side of main nozzle to make
the fuel lighter. When throttle valve is fully open, the amount of fuel is determined by the size of main jet.
The idle and off-idle passages keep feeding fuel as well as air to the engine.
3) High Speed Passage
E_MFS20C_ch04_090105.qxd 09.1.20 5:24 PM ページ 8
To Next Page
Loading...
Need help?
General
