Mercury 305 CID, Service Manual, Page: 444 / 967

MERCARB 2 BARREL CARBURETOR - 5B-5 90-823225--1 1096
Adjustable Accelerator Pump Lever
This new lever with will allow you to change the
amount of fuel delivered to the engine by the acceler-
ator pump. The hole closest to the lever’s shaft will
give the same amount of fuel as the single hole lever
did. The center hole gives approximately 0.5 cc less
fuel and the hole farthest away will give about 1.0 cc
less fuel.
73131
c
a
b
a - Full Accelerator Pump Stroke
b - 0.5 cc Less Fuel Per Stroke
c - 1.0 cc Less Fuel Per Stroke
The technician should be able to correct most “bog-
ging” problems with this 3-hole lever, providing the
“bogging” is caused by the carburetor. When install-
ing the 3-hole lever, remove any metal ball that some-
one may have put in the accelerator pump well to limit
pump travel. Also, make sure that the duration spring
on the accelerator pump is stock and hasn’t had sev-
eral coils cut off. Make sure the venturi cluster is the
correct one as outlined previously under “Specifica-
tions”.
High Altitude Re-Jetting
Engine flooding problems, at idle RPM, are generally
related to the altitude (above sea level) at which they
are operated.
If engine is running too rich at higher elevation, order
a smaller jet from the chart. A jet stamped “165” is a
1.65 mm jet.
Jet Size (mm)
1.30
1.35
1.40
1.45
1.50
1.55
1.60
1.65
1.70
1.75
1.80
1.85
1.90
Quicksilver Part Number
3302-811849
3302-811850
3302-811851
3302-9050
3302-811852
3302-811853
3302-810923
3302-9058
3302-9055
3302-811854
3302-811855
3302-811856
3302-811857
Description
This MerCarb carburetor is a two bore carburetor and
has a separate fuel feed for each venturi. This model
also is equipped with an electric choke. A removable
venturi cluster (secured to float bowl assembly) has
the calibrated main well tubes and pump jets built into
it. The venturi cluster is serviced as a unit. The ser-
viceable main metering jets are bleeds to properly
meter the correct fuel/air mixture to the engine.