Suzuki FU150SC Manual page 49

4-5 FUEL AND LUBRICATION SYSTEM
DIAPHRAGM AND PISTON OPERATION
Th ' . F
ibs seria! is a gona ie vente type, whose venturi cross section area is increased or decreased
ae ly 2 the piston valve @ which moves according to the negative pressure present on the
é eam side of the venturi @. Negative pressure is admitted into the diaphragm chamb
an orifice (3) provided in the piston valve @. "2 od
he cei eee overcomes the spring @)force, causing the piston valve (1) to rise to increase the
cpa us paver the air velocity from increasing. Thus, air velocity in the venturi passage is kept
ly constant for improved fuel atomization and for securing optimum ratio of fuel/air mixture. :
LOWER POSITION OF PISTON VALVE UPPER POSITION OF PISTON VALVE
Uf Y
Whyte
SSS
|
ASSEN
pape
@ Piston vaive
@) Diaphragm chamber
orifi
@) orifice
<=
NEGATIVE PRESSURE
(4) Spring
@) Venturi
@ Pilot air jet
Fuel/Air mixture
Fuel
@ Pilot jet
@ Pilot air jet
@ Pilot screw