14
ADJUSTMENTS

THROTTLE ADJUSTMENT

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 MANUAL FRICTION THROTTLE

•Loosen or tighte n wing nut on control plate until
throttle control moves with some resistance and still
remains in desired position when engine is running.
THROTTLE
CONTROL
CONTROL
PLATE
WING
NUT

TO ADJUST REMOTE THROTTLE

[1] Loosen casing clamp screw on con trol plate.
[2] Move wire and casing in direction of arrow to end of
travel.
[3] Move remote throttle control to FAST.
[4] Tighten casing clamp screw.
CASING
CLAMP
SCREW
CASING
WIRE

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.
Air cleaner and air cleaner cover must be assembled to
carburetor before starting engine. (Air cleaner is shown
removed in illustration below for clarity ONLY.)
The carburetor on this engine is equipped with an idle
mixture valve with a limiter (see inset ), which allows some
adjustment. Idle speed is not adjustable.

TO ADJUST CARBURETOR

[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.
IDLE MIXTURE
SCREW
WITH LIMITER
FIXED IDLE
SPEED SCREW
Note: Engines operated at approximately 3000 to 5000 feet
(900 to 1500 meters) above sea level may require a high
altitude carburetor nozzle. If erratic performance is ob-
served, contact a Briggs & Stratton Authorized Service
Dealer for cost to install/purchase a high altitude carburetor
nozzle.