Bajaj Discover 100M Service Station Manual page 110

CARBURETTOR CIRCUITS
m[ e n s)ATm hie Ap)D s)ATm
MAIN SYSTEM - High Speed System
Ap\ ) > g
Spring
TPS
hi[ l s[ º Tr
TPS
(Hall Sensor)
a[ r Ak| &
Air Screw
Magnet For
TPS
TPS
n& > m[ g n[ T
Throttle
Valve
Y\ i [ T l viÃv
Engine
Side
Air Fuel
Mixer
a[ r fy& a l m)~N
Needle Jet
n)Dl j[ T
Jet Needle
j[ T n)Dl
fy& a l l[ v l
Fuel Level
fli[ T
Float
Float fli[ T
Chamber
(Bowl) c[ À br {biul}
Pilot Jet
pieli[ T j[ T
• This System consists of jet needle, needle jet and main jet. To assist in atomization, an air bleed circuit is
incorporated in the main metering system and it aids fuel vaporization by introducing air into the fuel before it enters
the air stream.
• For VM type the midrange circuit is actually a combination of circuits that work together to achieve correct air fuel
mixture. The pilot circuit is still operational but its contribution to the total air fuel mixture is relatively less.
• The jet needle is a tapered needle attached to the throttle valve which points downward, through the centre of
carburettor venturi. The tapered end of the jet needle moves inside the needle jet which is located in the carburettor
body.
• The position of the jet needle relative to the needle jet determines the amount of fuel flowing through the clearance
between them.
• Changing the position of the jet needle relative to the slide (Throttle Valve) changes the air fuel mixture. The jet
needle is moved relative to the slide by changing the position of the ' e- clip' up or down in the grooves on the jet
needle. Moving the 'e-clip' towards the top of the needle has the effect of reducing the fuel flow, thus leaning out
the mixture. Bringing the 'e-clip' towards the lower grooves will have the effect of richening the mixture.
Discover 100 M
Service Station Manual
Y\ i [ T l k[ p
Cap Throttle
Side View
v[ º c& r )
Venturi
Petrol Inlet
p[ T ^ i [ l enl[ T
Air
Filter
Side
(For Main Jet)
Air
Intake
a[ r enT[ k
Needle
n)Dl viÃv
Valve
m[ e n j[ T
Main Jet
79
b)Ô[ uprn| )
Ti[ c Y)
Air
hvi {m[ e n j[ T miT[ }
Dealer Development Center
E
kl)p\
E Clip
2 nd from
Top Notch
(Std.)
Jet Needle
n)Dl j[ T
n)Dl j[ T
Needle Jet
Clearance
Between
Jet needle
& needle Jet
Akurdi Pune