8
. CARBURETOR
BR & M2 250 ENGINE
8-2 SLOW SYSTEM
This system supplies fuel during engine operation when the throttle valve
•
is closed
or slightly
opened. The fuel from the float chamber
‚
is metered by the pilot jet
ƒ
where it
mixes with air
coming in through the pilot air jet
„
. This mixture, rich with fuel, then goes up
through the pilot
passage to the pilot screw
…
. Part of the mixture is discharged into the main bore
through bypass
ports
†
. The mixture is metered by the pilot screw
…
and sprayed into the main bore
through the
pilot outlet port
‡
.
8-3 COASTING ENRICHMENT SYSTEM
The coasting enrichment system is included in the slow system. At the normal running
operation,
Joining of the air from upper part of then carburetor inlet side to pilot air passage
ˆ
which obtains
proper fuel/air mixture ratio. But if the throttle valve is closed suddenly, a large
negative pressure
generated in the cylinder which is applied to the diaphragm
‰
. The valve
Š
which
interlocks with the diaphragm
‰
closes an air passage
ˆ
, thus, the fuel/air mixture
ratio by controlling air
flow in the pilot circuit.
Summary of Contents for Bug Rider BR-250
Page 1: ...BR 250 BR 250SS M2 250 SERVICE MANUAL Manufactured by PGO of Motive Power Industry Co Ltd...
Page 34: ...4 CYLINDER HEAD VALVES 1 BR M2 250 ENGINE SCHEMATIC DRAWING...
Page 46: ...5 CYLINDER PISTON 1 BR M2 250 ENGINE SCHEMATIC DRAWING...
Page 55: ...6 DRIVE AND DRIVEN PULLEYS KICK STARTER 1 BR M2 250 ENGINE SCHEMATIC DRAWING...
Page 71: ...7 FINAL REDUCTION 1 BR M2 250 ENGINE SCHEMATIC DRAWING...
Page 82: ...8 CARBURETOR BR M2 250 ENGINE...
Page 90: ...9 A C GENERATOR STARTER CLUTCH 1 BR M2 250 ENGINE SCHEMATIC DRAWING...
Page 97: ...10 CRANKCASE CRANKSHAFT 1 BR M2 250 ENGINE SCHEMATIC DRAWING...
Page 103: ...10 CRANKCASE CRANKSHAFT 7 BR M2 250 ENGINE Torque 7 8 11 8N m Cam Chain Tensioner Slipper Bolt...
Page 105: ...11 COOLING SYSTEM 1 BR M2 250 ENGINE SCHEMATIC DRAWING...
