Yanmar 4LHA-HTP Operation Manual page 458

Chapter 3 Fuel Injection Equipment
4. Adjustment of Fuel Injection Pump and Governor
Pump rpm (N4)
Rack indicator scale
Measuring stroke
Injection volume
4-75 Check injection stop
Drive the pump at no l o a d maximum rpm ( N
governor control lever in t h e full load position, operate
the stop lever on the governor case, and make sure that
injection to all cylinders is stopped.
4-8 Adjustment of torque rise
There are some models w h i c h obtain torque rise with
angleich and torque springs incorporated in the fuel
injection pump as an injection volume increasing
mechanism.
Angleich spring
4-8.1 Models with angleich spring
For models with an angleich spring, perform this
adjustment after finishing the speed limit bolt adjust-
ment.
(1) The angleich spring is used as an assembly.
(2) Bring the governor control lever to the full load
position, and keep the pump speed at the specified
peak torque ( N ) .
5
(3) Remove the governor case cover in this state and
screw the angleich spring assembly to the tension
lever. Screw in from the contact position with the
governor lever (when control lever starts to move),
so that the injection volume at torque rise is within
the specified values [8 deg.)
200 rpm
13.5 ~ 14.5
500st
See separate service data
) . With
2
3-2-36
I 14 ±0.5
Torque rise stroke
R.
•o
(R.)
R3
(4) After completing the above, tighten the lock nut to
the specified torque, and mount the governor case
cover.
Lock nut tightening torque
NO TE: Make sure that the angleich bolt does not turn
with the locknut during
(5) Bring the fuel injection pump back to the rated
speed. Make sure that the control rack smoothly
displaces the torque rise stroke, and that rack
position ( R , ) and injection value are within the
specified value at (N!) rpm.
4-8.2 Models with torque spring
The torque rise spring is corporated in the fuel limit
bolt, and is used as an assembly.
Perform this adjustment after finishing the speed
limit bolt adjustment.
Dummy nut in contact
with torque spring.
J UL J
Dummy nut
Use the dummy nut during adjustment as shown in the
fig., without torque rise stroke, and remove it after
completing adjustment.
4LHA Series
N, N. N, N j
Pump speed (rpm)
N ( k g f ) m
24.5 ~ 29.4 (2.5-3.0)
tightening.
Torque rise
stroke clearance