Mariner 100, Service Manual, Page: 104 / 391

3A-17 90-13645--2 495 FUEL SYSTEM AND CARBURETION
Carburetor Adjustments
INITIAL STARTING ADJUSTMENT
After service or replacement of carburetor, turn low
speed mixture screw adjustment in (CLOCKWISE)
until it seats LIGHTLY – then back off (each
carburetor) the number of turns per model as
indicated, following:
70 H.P. --- 1-1/4
75 H.P. --- 1-1/2
80 H.P. --- 1-1/2 90 H.P. --- 1-1/2
100 H.P. --- 1-3/4
115 H.P. --- 1-1/2
This adjustment will permit engine startup.
LOW SPEED MIXTURE ADJUSTMENT
NOTE: Only the top two carburetors on four cylinder
models have adjustable idle mixture screws.
1. Start engine and allow to warm-up (run for several
minutes). Throttle back engine to idle for about
one minute to allow RPMs to stabilize.
2. With engine running at idle speed -- in water -- IN
FORWARD GEAR (prop on) -- turn low speed
mixture screw IN (clockwise) until engine starts to
“bog” down and misfire. Back out 1/4 turn or more.
22990
a
a - Low Speed Mixture Screw
3. Check for too lean mixture on acceleration.
4. DO NOT adjust leaner than necessary to attain
reasonably smooth idling. When in doubt, stay on
the slightly rich side of the adjustment.
CARBURETOR FLOAT ADJUSTMENT
1. If installed, remove carburetor as outlined in
“Carburetor Removal”, following.
2. Remove fuel bowl and gasket and check float
level as shown.
3. If necessary, adjust float level by bending metal
tab on float to which inlet needle is clipped.
a
b
11.1 mm
(7/16 in.)
a - Metal Tab
b - Inlet Needle