Nozzle Servicing - Toro Groundsmaster 300 Series Service Manual

Nozzle Servicing (Fig. 51)
The fuel from the injection pump flows through the
injection pipes to the nozzle. During the injection stroke
of the pump, pressurized fuel builds up in the nozzle.
When the pressure becomes sufficiently high, the noz-
zle valve opens and a spray of fuel is injected into the
combustion chamber where it is ignited due to the heat
produced by the cylinder compression. If the nozzle
does not function properly, starting failure, low power
output, or engine knocking can occur.
IMPORTANT: When servicing the injection nozzles
make certain that the engine and fuel delivery pipes
are clean in order to prevent dirt from entering the
cylinder or nozzle. Do not mix components of one
nozzle with another.
Nozzle Testing
Refer to "Nozzle Tests" for complete instructions.
Nozzle Removal and Disassembly
1. Remove the fuel overflow line from the
nipple on the nozzle body.
2. Disconnect the fuel injection pipe from the nozzle
body.
3. Remove the two bolts which pass through the nozzle
flange and remove the nozzle assembly from the cylin-
der head. Remove the copper nozzle holder gasket.
NOTE: Further disassembly of the nozzle is not required
for testing purposes.
4. Secure the retaining nut in a vise which is equipped
with aluminum or brass jawplates and loosen the nozzle
body with a wrench.
5. Remove the nozzle body, shim, pressure spring,
flange, pressure pin and distance piece.
6. Remove the nozzle from the retaining nut. If it is
difficult to remove, tap it lightly with a rubber or wooden
mallet. Be careful not to hit or damage the protruding tip
of the nozzle needle valve.
Inspection and Cleaning
1. Clean the inside and outside of the retaining nut in
clean diesel fuel to remove carbon or fuel deposits.
Inspect the lower seating surface for rust or damage.
The sealing area may be restored with emery cloth.
®
Groundsmaster 300 Series
2. Remove carbon or lacquer deposits from the nozzle
by cleaning in clean diesel fuel. Stubborn deposits may
be removed with brass wired brush.
IMPORTANT: Do not use a steel brush, steel wool,
etc. or the nozzle hole or pin tip may become dam-
aged and need to be replaced.
3. Clean the flange, body, shim, spring, pin and distance
piece in clean diesel fuel. Replace any worn or damaged
parts.
Reassembly and Test
1. Install the nozzle assembly, distance piece and pres-
sure pin into the retaining nut.
2. Install the shim, pressure spring and flange in the
body. Assemble the body to the retaining nut. Torque the
body and nut to 43 - 58 ft-lb (6 - 8 KgM).
3. Test the reassembled nozzle for proper operation.
Refer to "Nozzle Tests."
Installation
1. Install a new nozzle holder gasket onto the nozzle.
2. Position the nozzle assembly on the head and install
the bolts through the flange. Alternate tightening the
bolts to ensure even pressure on both sides of the
flange. Torque the bolts to 11 - 15 ft-lb (1.5 - 2 KgM).
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Figure 51
Fuel System Service