Kubota WSM L3560, Workshop Manual

Page: 126 / 801

ENGINE
L3560, L4060, L4760, L5060, L5460, L6060, WSM
1-M11
Overflow Valve
When the pressure of fuel delivered from the feed
pump rises above a prescribed amount, the overflow
valve has a function of returning fuel to the tank and is
made up of a valve body (2), valve piston (5), spring (3),
and ball (1).
When fuel pressure increases and exceeds the force
of the spring, the valve piston is pushed. Here, the fuel
passes through the port (4) provided in the valve body
and returns to the fuel tank.
Therefore, the pressure in the suction control valve
is stabilized and fuel flow is accurately adjusted.
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Zero Delivery Drain
The zero delivery drain (1) has a function of
preventing fuel flow to the pressurizing part when no fuel
is being delivered.
Though the suction control valve is set to no flow, a
small amount of fuel flows to the pressurizing part. The
zero delivery drain is provided to prevent this and this
small amount of fuel is returned through the zero delivery
drain and returned to the fuel tank.
NOTE
• Other than no delivery, fuel is delivered to the
pressurizing part based on the amount of throttle
and very little flows to the zero delivery drain.
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(1) Ball
(2) Valve Body
(3) Spring
(4) Port
(5) Valve Piston
[A] While Open
[B] While Closed
(1) Zero Delivery Drain
KiSC issued 03, 2016 A