Kubota M5040, Workshop Manual

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1-M11
M5040, M6040, M7040, WSM ENGINE
5. FUEL SYSTEM
[1] GOVERNOR
The engine employs the separated fuel injection
pump in combination with Kubota’s own small multi-
function mechanical governor, which enables more
dependability.
It also employs the torque limiting mechanism to
control the maximum peak torque so that it complies with
the regulations of exhaust gas.
This mechanism maintains engine speed at a
constant level even under fluctuating loads, provides
stable idling and regulates maximum engine speed by
controlling the fuel injection rate.
This engine uses a mechanical governor that controls
the fuel injection rate at all speed ranges (from idling to
maximum speed) by utilizing the balance between the
flyweight’s centrifugal force and spring tension.
A governor shaft for monitoring engine speed is
independent of the injection pump shaft and rotates at
twice the speed of conventional types, providing better
response to load fluctuation and delivering greater
engine output.
W1013830
Q
At Start
The stop solenoid (energized-to-run type) is powered
to release the stop lever.
As no centrifugal force is applied to flyweight (2), low
tension of start spring (1) permits control rack to move
the starting position, supplying the amount of fuel
required to start the engine.
W1013967
(1) Start Spring (2) Flyweight
KiSC issued 06, 2008 A