Repair Service Manual

REPAIR MANUAL
1
KUBOTA Z402 and Z602 engines
Upon starting:
Spring 2 drives lever 3 to the maximum flow position, the control rod is in the maximum flow
position. When the engine starts, the centrifugal force applied to the regulator is stronger that the
cold start spring, hence lever 3 is pushed to the minimum flow position, and the control rod pushes
the idle spring 11.
At idle:
Centrifugal force applied to the regulator is sufficient to maintain lever 3 and the control rod on idle
spring 11. The spring 11 ensures idle running stability.
At full load:
Upon acceleration request, lever 1 applies a tension on spring 2, which drives lever 5. Lever 5
drives lever 3, and moves the flow control rod in max load position. When speed reaches the
maximum, the centrifugal force applied to the regulator becomes higher than that applied by spring
4, the control rod moves to a flow reduction.
Upon engine stop:
The engine stop lever pushes lever 3 in min flow position, the force applied to the lever is
important enough to completely compact the idle spring, hence cutting engine injection.