Mercury 305 CID - Carburetor Malfunctions

1C-14 - TROUBLESHOOTING 90-823225--1 1096
Carburetor Malfunctions
Symptoms Cause
Fl di
A. Needle and seat
Fl di
B. Float adjustment
Fl di
C. Saturated float
Flooding
D. Gaskets leaking
E. Cracked fuel bowl
F. Fuel percolation
G. Automatic choke
R h idl
2. A. Idle RPM too low
R h idl
B. Idle mixture screws
R h idl
C. Idle passages dirty
Rough idle
D. Throttle valves not closing
E. Engine flooding
F. Vacuum leak
G. Throttle body heat passages plugged
Hii l i fl
A. Accelerator pump
Hii l i fl
B. Leaking gaskets
Hii l i fl
C. Automatic choke
Hii l i fl
D. Power piston or power valve
Hesitation or acceleration flatness
E. Throttle valves
F. Throttle body heat passages plugged
G. Main metering jets
H. Float adjustment
I. Secondary air valve wind-up