4-6 FUEL AND LUBRICATION SYSTEM
SLOW SYSTEM
This system supplies fuel during engine operation when the piston valve 1 is fully closed or slightly open.
The fuel from the float chamber 2 is metered by the pilot jet 3 where it mixes with air coming in through the
pilot air jet 4. This mixture, rich with fuel, then goes up through the pilot passage to the pilot screw 5. A part
of the mixture is discharged into the main bore from the bypass ports 6. The remainder of the mixture is
metered by the pilot screw 5 and sprayed into the main bore through the pilot outlet 7.
COASTING ENRICHMENT SYSTEM
The coasting enrichment system is included in the slow system. At normal operation, joining of the air from
carburetor inlet side pilot air passage 8 which obtains the proper air/fuel mixture ratio. When the piston
valve is closed suddenly, a high vacuum, which is generated in the main bore, is applied to the diaphragm 9.
The valve 0 which interlocks with the diaphragm 9 closes the air passage 8, and thus, produces an air/
fuel mixture that is rich with fuel. By controlling air flow in the pilot circuit, this system is able to keep combus-
tion constant by varying the air/fuel mixture ratio.
To Next Page
Loading...
Need help?
General
