Suzuki DR650SE - Main System

FUEL AND LUBRICATION 4·8
MAIN SYSTEM
As throttle valve CD is opened, engine speed rises, and this increases negative pressure in the ventu-
ri ®. Consequently the piston valve @ moves upward.
Meanwhile, the fuel in float chamber @ is metered by main jet @ , and the metered fuel enters nee-
dle
jet ® , in which it mixes with the air admitted through main air jet ® to form an emulsion.
The emulsified fuel then passes through the clearance between needle jet ® and jet needle (J) , and
is discharged
into the venturi ®, in which it meets main air stream being drawn by the engine.
Mixture proportioning is accomplished in needle jet ® ; the clearance through which the emulsified
fuel must flow in large or small, depending ultimately on throttle position.
<18::::::::::::::::::::::J Fuel/Air mixture
~ Fuel