Main System - Suzuki Katana 1100 Service Manual

FUEL AND LUBRICATION SYSTEM 4-6
MAil\! SYSTEM
As throttle valve is opened, engine speed rises, and this increases vacuum in the venturi. Consequently
the piston valve moves upward.
Meanwhile, the fuel in float chamber is metered by main jet, and the metered fuel enters needle 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, 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 is large or small, depending ultimately on throttle position.
Throttle valve ­
-I-_~
_ _
+----+~-- Piston valve
I+--+!+-----f----t----Jet need Ie
'i'I!=~~:i::::==::T---
M aina ir jet
Main jet
¢J
Air
<fJ
Fuel/Air mixture
• Fuel