Briggs & Stratton 28B700 - Manual (Page 14)

14
ADJUSTMENTS
CONTROL ADJUSTMENTS
If the engine does not start or if it runs roughly, the remote
throttle control may need adjustment. See your authorized
Briggs & Stratton dealer or follow the instructions below.
WARNING
Prevent unintentional starting.
Before performing adjustments:
•
Remove spark plug wire from spark plug.
•
Disconnect battery at negative terminal (only
engines with electric start).
TO ADJUST REMOTE THROTTLE
[1] Move remote throttle control to FAST position.
[2] Hole in governor control lever (located just behind
governor control plate) must align with hole in
governor control plate, as illustrated above.
[3] If holes do not line up, loosen casing clamp screw
and then move governor control rack until it does.
[4] Tighten casing clamp screw.
[5] Check operation of throttle. Move throttle control to
STOP position.
[6] Governor control lever must make good contact with
stop switch (if equipped). Readjust if necessary.
HOLE IN
GOVERNOR
CONTROL PLATE
GOVERNOR
CONTROL LEVER STOP
SWITCH
GOVERNOR CONTROL RACK CASING CLAMP SCREW
TO ADJUST REMOTE CHOKE
[1] Hold choke control to CHOKE or START position.
[2] Loosen casing clamp screw.
[3] Pull casing, wire and choke lever in direction of
arrow to end of travel.
[4] Tighten casing clamp screw.
CASING
CLAMP
SCREW
CARBURETOR ADJUSTMENT
WARNING
The manufacturer of the equipment on which this
engine is installed specifies top speed at which the
engine will be operated. DO NOT EXCEED this speed.
Differences in fuel, temperature, altitude or load may require
minor carburetor adjustment. Air cleaner and its cover must
be assembled to carburetor before starting engine.
The carburetor on this engine is equipped with an idle
mixture valve with a limiter (see inset), which allows some
adjustment, and an idle speed adjustment screw.
TO ADJUST CARBURETOR
IDLE MIXTURE
VALVE
WITH LIMITER
CARBURETOR
THROTTLE
LEVER
IDLE
SPEED
SCREW
[1] To adjust idle speed, start engine and warm up
about 5 minutes.
[2] With engine running, place equipment throttle
control in SLOW position.
[3] Rotate carburetor throttle lever against the idle
speed screw and hold it. Turn idle speed screw to
obtain 1750 rpm (use a tachometer).
[4] Then rotate idle mixture valve full travel clockwise
and then counterclockwise.
Note: DO NOT remove limiter caps. DO NOT
force beyond limits.
[5] Then, position idle mixture valve in middle of travel.
[6] Check idle speed. Re-adjust to 1750 rpm, if needed.
[7] Move throttle control to FAST position. Engine
should accelerate smoothly. If it does not, adjust
idle mixture valve counterclockwise 1/8 turn.
Note: Engines operated at approximately 3000 to 5000 feet
(900 to 1500 meters) above sea level may require a high alti-
tude carburetor nozzle. If erratic performance is observed,
contact a Briggs & Stratton Authorized Service Dealer for cost
to install/purchase a high altitude carburetor nozzle.