L2501 ENGINE – FUEL SYSTEM

Injection Timing
1. Remove the stop solenoid.
2. Remove the fuel tank, injection pipes and glow plugs.
3. Set the speed control lever to maximum fuel discharge position.
(Reference)
• Turn the flywheel with screwdriver.
4. Turn the flywheel counterclockwise (facing the flywheel) until the fuel fills up to the hole of the delivery valve holder for 1st cylinder.
5. Turn the flywheel further and stop turning when the fuel begins to flow over, to get the present injection timing.
6. (The flywheel has mark 1TC and four lines indicating every 0.09 rad (5 °) of crank angle from 0.17 rad (10 °) to 0.44 rad (25 °) before mark 1TC) Calculate the angle which the center of the window points out. If the calculation differs from specified injection timing, add or remove the shim to adjust.
(Injection Timing)

NOTE
The sealant is applied to both sides of the soft metal gasket shim. The liquid gasket is not required for assembling.
Shims are available in thickness of 0.20 mm (0.0079 in.), 0.25 mm (0.098 in.) and 0.30 mm (0.012 in.). Combine these shims for adjustments.
Addition or reduction of shim (0.05 mm, 0.002 in.) delays or advances the injection timing by approx. 0.009 rad (0.5 °).
In disassembling and replacing, be sure to use the same number of new gasket shims with the same thickness.

CAUTION
Check the injection pressure and condition after you make sure that there is no one in the direction of the fumes.
If the fumes from the nozzle directly touches the human body, they can cause damage to the cells and blood poisoning.
Use eyes protector on eyes when inspecting the high pressure fuel from the fuel injection nozzle.
Set the protection board for jetted fuel near the tractor when inspecting the high pressure fuel from the fuel injection nozzle.
Use face protector on face when inspecting the high pressure fuel from the fuel injection nozzle.
Use leather gloves or protector on hands, arm covers on arms and protector on body when inspecting the high pressure fuel from the fuel injection nozzle.

Nozzle Fume Condition
1. Set the injection nozzle to a nozzle tester, and check the condition of the fumes from the nozzle.
2. If the fume condition is bad, replace the injection nozzle assembly.
(A) Good
(B) Bad
(a)1.3 rad (72 °)

Fuel Injection Pressure
1. Set the injection nozzle to a nozzle tester.
2. Slowly move the tester lever to measure the pressure at which the fuel start to jet out from the nozzle.
3. If the measurement is out of the factory specifications, replace the injection nozzle assembly.

Valve Seat Tightness
1. Set the injection nozzle to a nozzle tester.
2. Increase the fuel pressure, and keep it at 16.7 MPa (170 kgf/cm2, 2420 psi) for 10 seconds.
3. If you find a fuel leakage, replace the injection nozzle assembly.

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