Kubota MX5100 Workshop Manual page 113

MX5100, WSM
Fuel Tightness of Delivery Valve
1. Remove the engine stop solenoid.
2. Remove the injection pipes and glow plugs.
3. Set a pressure tester to the fuel injection pump.
4. Install the injection nozzle (2) jetted with the proper injection
pressure to the injection pump pressure tester (1).
5. Run the starter to increase the pressure.
6. Stop the starter when the fuel jets from the injection nozzle. After
that, turn the flywheel by the hand and raise the pressure to (IDI
: approx. 13.73 MPa (140.0 kgf/cm
18.63 MPa (190.0 kgf/cm
7. Now turn the flywheel back about half a turn (to keep the plunger
free). Maintain the flywheel at this position and clock the time
taken for the pressure to drop from (IDI : 13.73 to 12.75 MPa
(140.0 to 130.0 kgf/cm
MPa (190.0 to 180.0 kgf/cm
8. Measure the time needed to decrease the pressure from (IDI :
13.73 to 12.75 MPa (140.0 to 130.0 kgf/cm
(DI : 18.63 to 17.65 MPa (190.0 to 180.0 kgf/cm
psi)).
9. If the measurement is less than allowable limit, replace the pump
with new one or repair with a Kubota-authorized pump service
shop.
Factory spec.
Fuel tightness of delivery
valve
Allowable limit
NOTE
• Never try to disassemble the injection pump assembly. For
repairs, you are strongly requested to contact a Kubota-
authorized pump service shop.
(1) Injection Pump Pressure Tester
(2) Injection Nozzle
Nozzle Spraying Condition
CAUTION
• Check the injection pressure and condition after confirming
that there is nobody standing in the direction the fume goes.
• If the fume from the nozzle directly contacts the human
body, cells may be destroyed and blood poisoning may be
caused.
1. Set the injection nozzle to a nozzle tester, and check the nozzle
spraying condition.
2. If the spraying condition is defective, replace the nozzle piece.
(a) Good
1-S21
2
, 1991 psi)), (DI : approx.
2
, 2702 psi)).
2
, 1991 to 1849 psi)), (DI : 18.63 to 17.65
2
, 2702 to 2560 psi)).
2
, 1991 to 1849 psi)),
10 seconds
13.73 → 12.75 MPa
140.0 → 130.0 kgf/cm
1991 → 1849 psi
5 seconds
13.73 → 12.75 MPa
140.0 → 130.0 kgf/cm
1991 → 1849 psi
(3) Protection Cover for Jetted Fuel
(b) Bad
ENGINE
2
, 2702 to 2560
2
2
W1017786
W10181310