Carburetor Adjustment - Briggs & Stratton Vanguard 470000 Series Operating & Maintenance Instructions

MAINTENANCE
CLEANING DEBRIS
Daily or before every use, clean accumulated debris from engine.
Keep linkage, springs and controls clean. Keep area around and
behind muffler free of any combustible debris.
Model 470000: Use the handle on the radiator screen to lift off for
cleaning. Clean screen thoroughly and clean radiator fins.
Model 540000: Remove front carburetor cover, and clean around
intake manifold and carburetor.
CAUTION: Do not use water to clean engine parts. Water could
contaminate fuel system. Low pressure compressed air may be
used, be careful not to damage radiator fins.
WARNING
FUEL FILTER
WARNING
PART NO. 807241
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ADJUSTMENTS

CARBURETOR ADJUSTMENT

Differences in fuel, temperature, altitude or load may require minor
carburetor adjustment. Air cleaner and air cleaner cover must be
assembled to carburetor before starting engine.
The carburetor on this engine is low emission. The carburetor is
equipped with an idle speed adjustment screw. The Model
470000 is equipped with an idle mixture valve with a limiter (see
inset), which allows some adjustment. DO NOT remove limiter
caps. DO NOT force beyond limit.
TO ADJUST CARBURETOR
[1] Start engine and warm up approximately 5 minutes before
adjusting.
[2] Place throttle control in SLOW position.
[3] Rotate carburetor throttle lever against the idle speed screw
and hold it.
[4] Turn idle speed screw to obtain 1500 rpm
[5] Model 470000 Only: While still holding carburetor throttle
lever against idle speed screw, set cylinder #1 idle mixture
valve to obtain highest speed. Then set cylinder #2 idle
mixture valve to obtain highest speed. Do not force beyond
limit. Do not remove limiter caps.
[6] Model 470000 Only: Release carburetor throttle lever.
Move throttle control to FAST position. Engine should
accelerate smoothly. If it does not, readjust idle mixture
valves slightly counterclockwise.
Engine parts should be kept
clean to reduce the risk of over-
heating and ignition of accumu-
lated debris.
Drain fuel tank or close fuel shut-off
valve before replacing fuel filter.
Otherwise, fuel can leak out,
creating a fire/explosion hazard.
When replacing fuel filter, ensure
clamps are tight and fuel flows into
the same direction as the arrow
marked FLOW.
RADIATOR
SCREEN
HANDLE
CLEAN DEBRIS
MUFFLER/FUEL SYSTEM
WARNING
(cap, hoses, tanks, filters, etc.) must be the same as original
parts, otherwise fire can occur.
WARNING
engine will be operated. DO NOT EXCEED this speed.
WARNING
Note: Engines operated at about 3000 feet (900 meters) or higher above
sea level may require a high altitude carburetor main jet. If erratic perfor-
mance is observed, contact a Briggs & Stratton Authorized Service
Dealer for cost to install/purchase a high altitude carburetor main jet.
CARBURETOR
THROTTLE
LEVER
IDLE SPEED
SCREW
CYL # 2
Only Model 470000 carburetor has idle mixture valves
14
CLEAN DEBRIS
CLEAN DEBRIS
Replacement parts for the muffler
must be the same and installed in
the same position as the original
parts, otherwise fire can occur.
Replacement parts for fuel system
The manufacturer of the equipment
on which this engine is installed
specifies top speed at which the
Engine will be running to perform
this adjustment. Keep away from all
rotating and moving parts.
LIMITER
CAP
IDLE MIXTURE
VALVES
CYL # 1