11-1
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Specifications subject to change without notice - Check our website for valuable information including videos, workshop and operations manuals. www.jjamusements.com
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ENDURANCE CL
UTCH PLA
TES
TM
CARBURETOR
OVERVIEW
Overview ......................................................... page 11-1
Identifying carburetor items .............................. page 11-3
Carburetor check sheet......................................page 11-7
CARBURETOR
This simple device has one purpose: atomize fuel and air into a combustible ratio.
When working with the carburetor, always keep in mind the following:
Most carburetor problems are from contamination (dirt, rust, sludge, etc). If the engine will not start while fuel is
present at carburetor bore (venturi) and the spark plug is wet, your problem is usually elsewhere as long as fuel is fresh.
The idle circuit has the smallest orifices (jets) and passages in the carburetor and is therefore the most prone to
clogging.
Air leaks in the intake track, blown gaskets or a cracked insulator block will cause problems when the pressure
differential (engine vacuum) is highest. This occurs when the throttle blade is closed and the engine is in the idle
position. The pressure differential begins to decrease when the throttle begins to open, and is lowest when the throttle
bore is wide open. For this reason, intake air leaks have minimal effect on high-speed operation.
NEEDLE AND SEAT (FLOAT VALVE)
This device has one job: to control the amount of fuel in the float bowl reservoir. If the float bowl is overflowing, there
is a problem with the float valve/float circuit. Dirt or wear of the float valve is most likely.
FLOAT
The fuel level when properly set keeps a stable amount of fuel available for delivery. A higher float level will cause a
richer mixture throughout the range; this would be a small amount of change and hard to detect in most cases.
NOTE: After repairing a carb overflow problem, ALWAYS CHANGE THE ENGINE OIL. Fuel will have overflowed and
run into the crankcase, severely diluting the oil. The float valve seat and hinge assembly are not replaceable.
This manual does not cover every aspect of
carburetion. The Honda service manual covers
carburetion in greater detail and can be purchased
from J&J.
For GX-270, 340-240 engines use #61Z5f00E3
For GX-160 and 200 engines use #50300690.
