RG27/35/37 Operation • Service • Maintenance
48
Troubleshooting
Engine
Use the following information to determine the source and
solution to problems you may encounter related to the engine.
This information can also be found in the Kubota Engine
Operator’s Manual that shipped with this machine.
Service
When it is difficult to start the engine
Cause
Countermeasures
Fuel is thick and
doesn’t flow
►Check the fuel tank and fuel filter. Remove
water, dirt, and other impurities.
►As all fuel will be filtered by the filter, if there
should be any water or other foreign matters
on the filter, clean the filter with kerosene.
Air or water
mixed in the
fuel system
►If air is in the fuel filter or injection lines, the
fuel pump will not work properly. To maintain
proper fuel injection pressure, check carefully
for loosened fuel line couplings, loose cap
nut, etc.
►Loosen joint bolt stop fuel filter and air vent
screws of fuel injection pump to eliminate all
the air in the fuel system.
Thick carbon
deposits on
orifice of injec-
tion nozzle
►This is caused when water or dirt is mixed
in the fuel. Clean the nozzle injection place
being careful not to damage the orifice.
►Check to see if the nozzle is working prop-
erly or not. If not, install a new nozzle.
Valve clearance
is wrong
►Adjust the valve clearance to 0.145 to 0.185
mm (0.0057 to 0.0072 in.) when the engine
is cold
Leaking valves
►Grind valves.
Fuel injection
timing is wrong
►Adjust injection timing
The injection timing 0.3 rad (18°) before top
dead center.
Engine oil
become thick
in cold weather
and engine
cranks slow
►Change grade of oil according to the
weather (temperature)
Low Compres-
sion
►Bad valve or excessive wear of rings, pis-
tons, and liners cause insufficient compres-
sion. Replace with new parts.
Battery is
discharged and
the engine will
not crank
►Charge battery.
►In winter, always remove battery from the
machine, charge fully and keep indoors.
Reinstall in machine at times of use.
When engine suddenly stops
Cause
Countermeasures
Lack of fuel
►Check the fuel tank and refill with fuel, if
necessary.
►Also check the fuel system for air or leaks.
Bad nozzle
►If necessary, replace with a new nozzle.
Moving parts
are overheated
due to shortage
of lubrication
oil or improper
lubrication
►Check amount of engine oil with oil level
gauge.
►Check lubricating oil system.
►At every 2 times of oil change, the oil filter
cartridge should be replaced.
►Check to see if the engine bearing clear-
ances are within factory specs..
When output is insufficient
Cause
Countermeasures
Carbon stuck
around orifice of
nozzle place
►Clean orifices and needle valve being very
careful not to damage the nozzle orifice..
►Check nozzle to ensure that It is good. If
not, replace the nozzle..
Compression is
insufficient.
Leaking valves
►Bad valve and excessive wear of rings,
pistons, and liners cause insufficient com-
pression. Replace with new parts..
►Grind valves..
Fuel is insuf-
ficient
►Check fuel system..
Overheating of
moving parts
►Check lubricating oil system.
►Check to see if lubricating oil filter is work-
ing properly.
►Filter element deposited with impurities
would cause poor lubrication. Change
element.
►Check that the clearance of bearings are
within factory specs.
►Check injection timing.
Valve clearance
is wrong
►Adjust the valve clearance to 0.145 to
0.185 mm (0.0057 to 0.0072 in.) when the
engine is cold
Air cleaner is
dirty
►Clean the element every 100 hours of
operation.
Fuel injection
pressure is
wrong
►Adjust to proper pressure:
13.7 Mpa (140kgf/cm2, 1991 psi)
Injection pump
wear
►Do not use poor quality fuel as it will cause
wear of the pump. Only use No.2-D diesel
fuel.
►Check the fuel injection pump element
and delivery valve assembly and replace as
necessary.
When color of exhaust is especially bad
Cause
Countermeasures
Fuel governing
device bad
►Contact dealer for repairs.
Fuel is
extremely poor
quality
►Select good quality fuel.
Use No.2-D diesel fuel only..
Nozzle is bad
►If necessary, replace with a new nozzle.
Combustion is
incomplete
►Cause is poor atomization, improper
injection timing, etc. Because of trouble in
injection system or in poor valve adjustment
or compression leakage, poor compression,
etc. Check for cause..
Summary of Contents for Super Jr RG27
Page 47: ...RG27 35 37 Operation Service Maintenance 800 392 2686 47 Maintenance Notes ...
Page 50: ...RG27 35 37 Operation Service Maintenance 50 Wiring Schematic ...
Page 51: ...RG27 35 37 Operation Service Maintenance 800 392 2686 51 Wiring Schematic ...
Page 54: ...RG27 35 37 Operation Service Maintenance 54 Hydraulic Schematic RG37 802846 RF T T P P ...
Page 56: ...RG27 35 37 Operation Service Maintenance 56 Specifications SERVICING TAPER BUSHINGS ...
Page 63: ...RG27 35 37 Operation Service Maintenance 800 392 2686 63 ...