Kubota WSM 05-E4B Series Workshop Manual page 84

4. ENGINE
(1) Max. torque limiter
(2) Start spring
(3) Governor spring
(4) Fork lever shaft
(5) Flyweight
(At rated operation)
When the engine operates, the fork lever 2 (9) and the
floating lever (7) are moving with the fork lever 1 (6)
due to the tension of the governor spring (3).
During the time, the torque pin (8) is pressed into the
floating lever by centrifugal force of the flyweight (5).
The fork lever 2 (9) comes in contact with the fuel
limitation bolt (10), and the fuel injection pump supplies
a fuel necessary for rated operation.
4-2
(6) Fork lever 1
(7) Floating lever
(8) Torque pin
(9) Fork lever 2
(A) Fork lever assembly
(1) Max. torque limiter
(6) Fork lever 1
(7) Floating lever
(Overloaded operation)
The amount of the movement of the fork lever
assembly is limited with the fuel limitation bolt (10) and
can-not be moved in the direction of the fuel increase.
As overload reduces the centrifugal force of the
governor weight, which is pressing the torque pin (8)
into the floating lever (7), the floating lever pushes the
fork lever 1 (6) in the way to increase the fuel supply
with the help of the torque spring tension.
The fuel supply increases (b) in relation to the degree
of the torque pin motion, thus preventing the engine
speed from dropping.
At the time, the max. torque limiter (1) prevents
superfluous fuel supply and suppresses the generation
of black smoke.
MECHANISM
1. Engine body
(9) Fork lever 2
(10) Fuel limitation bolt
05-E4B SERIES,05-E4BG SERIES
KiSC issued 03, 2023 A