FUEL SYSTEM
COMPONENTS
COMPONENTS
The carbureted fuel system consists of the follow-
ing components:
• Primer solenoid
• Primer
pump
(25
TE
and 25/30 R Models)
• Fuel
pump
• Carburetor
• Intake manifold assembly
Primer Solenoid
REMOTE ELECTRIC MODELS
Fuel mixture enrichment for cold starting
and
run-
ning is provided
by
a solenoid operated fuel
primer valve. When activated at the key switch,
the
valve diverts fuel
from
the fuel pump directly to
the carburetor and/or the intake manifold.
Primer Pump
25
TE
AND 25/30 R MODELS
Fuel mixture enrichment for cold starting and
warm-up
is
provided
by
a manually operated
primer pump.
Pull the primer knob through
its
full
stroke twice
and
return
to
the warm-up position to
operate the primer.
140
1
1. Manual primer
DR3753A
2.
Warm-up position (colored groove)
Fuel Pump
The fuel pump is a diaphragm-displacement type
and
is
operated
by
changes
in
crankcase pres-
sure. A pulse hose connects the pump to the cyl-
inder/crankcase. Alternately, vacuum and
pressure
in
the crankcase are transmitted to the
pump diaphragm.