Toro Groundsmaster 455-D Service Manual page 48

Nozzle Leakage Test
A nozzle that leaks fuel from the nozzle orifice must be
replaced.
1. Securely fasten the nozzle to the adapter.
2. Wipe all fuel from the nozzle.
3. Operate the pump until the pressure is approximately
2
20 bar or kg/cm (280 psi) below opening pressure.
Maintain this pressure to the nozzle.
4. Watch for leaks where the threaded nozzle body
threads into the retaining nut. Leaks in this area would
indicate a bad seat between the distance piece and/or
the body or nozzle assembly.
5. If leakage occurs, verify that the body is tightly fas­
tened in the retaining nut. If the leak continues, replace
the nozzle.
6. While pressure is being applied, watch for an ac­
cumulation of fuel at the tip of the nozzle (Fig. 35). A
small amount of fuel may be present due to a previous
chattering test - this would be normal. If the fuel accumu­
lates and drips down during the test (about ten seconds)
the nozzle assembly is defective and must be replaced.
Spray Test
For proper combustion, the nozzle must effectively
atomize the injected fuel.
1. Operate the pump handle quickly (4 - 6 strokes per
second).
2. Observe the injector nozzle spray. The spray pattern
should be finely atomized in a broad, straight stream
(Fig. 36).
3. If the nozzle fails to spray properly, it must be cleaned,
repaired or replaced.
Engine
Good
Good
broad spray
fine mist
straight
Page 3 - 30 Rev. B
Bad Bad
Figure 35
Bad Bad
narrow spray angled spray
streaky mist
Figure 36
Groundsmaster 455-D