Bajaj pulsar DTS-i, Service Station Manual

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CARBURETTOR CIRCUITS
Pulsar 150/180 DTS-i
Service Station Manual
80
Dealer Development Center
Akurdi Pune
Starter Circuit :
Constant Velocity Carburettor
1. Plunger Cap
2. Diaphragm Cap
3. Diaphragm Piston Valve
4. Piston Valve with Jet Needle
Air inlet
for choke
Towards
Engine
Function
The function of starter circuit is to provide rich air fuel mixture on starting / cold starting. At cold engine
condition the air is dense also the engine parts are cold enough this does not allow the petrol to vaporize
properly this leads to starting trouble.
Construction
Working
The Starter Circuit consists of a starter jet and a plunger. The starter jet is used to meter the fuel and a
plunger that opens an air passage from the inlet of the carburettor (underneath the diaphragm) which passes
the mixture to the manifold.
On pulling the choke lever the plunger is lifted by a cable. This uncovers the fuel passage that leads to the
starter jet, air inlet passage and the outlet passage towards the manifold. This creates enough suction to
draw fuel up from the bowl into the mixing chamber (below the plunger). Here the fuel is mixed with the air
Cut Section View
of Mixing Chamber
Towards
Engine
1. Plunger
2. Mixing Chamber