Yanmar 6CXM-GTE, Service Manual

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3. Engine's
output is
insufficient
Defective injection
timing, and
other failures (1) Knocking sounds caused by improper (too early) injection timing.
(2) Engine overheats or emits large amount of smoke due to improper
(too late) injection timing.
(3) Insufficient fuel delivery from feed pump.
Inspect and adjust
Inspect and adjust
Repair or replace
Nozzle movement is
defective. (1) Case nut is loose.
(2) Defective injection nozzle performance.
(3) Nozzle spring is broken.
(4) Excessive oil leaks from the nozzle. Inspect and tighten
Repair or replace nozzle
Replace
Replace nozzle assembly
Injection pump is
defective. (1) Max delivery limit bolt is screwed in too far.
(2) Plunger is worn.
(3) Injection amount is not uniform.
(4) Injection timings are not even.
(5) The levers of the governor and the control rack of the injection
pump are improperly lined up.
(6) Delivery stopper is loose.
(7) Delivery packing is defective.
(8) Delivery valve seat is defective.
(9) Delivery spring is broken.
Adjust
Replace
Adjust
Adjust
Repair
Inspect and tighten
Replace packing
Repair or replace
Replace
4. Idling is rough. (1) Movement of control rack is defective.
1) Stiff plunger movement or sticking
2) Rack and pinion fitting is defective.
3) Movement of governor is improper.
4) Delivery stopper is too tight.
(2) Uneven injection volume
(3) Injection timing is defective.
(4) Plunger is worn and fuel injection adjustment is difficult.
(5) Governor spring is too weak.
(6) Feed pump can't feed oil at low speed.
(7) Fuel supply is insufficient at low speed due to clogging of fuel filter.
Repair or replace
Repair
Repair
Inspect and adjust
Adjust
Adjust
Replace
Replace
Repair or replace
Disassemble and clean, or
replace element.
5. Engine runs at high speed,
and cuts out at low speed.
(1) The wire or rod of the accelerator is caught.
(2) Control rack is caught and can't be moved. Inspect and repair
Inspect and repair
6. Engine does not reach max. rpm. (1) Governor spring is broken or excessively worn.
(2) Injection performance of nozzle is poor. Replace
Replace or repair
7. Loud knocking (1) Injection timing is too early or too late.
(2) Injection from nozzle is improper.
Fuel drips after each injection.
(3) Injection pressure of nozzle is too high.
(4) Uneven injection volume.
(5) Engine overheats, or insufficient compression.
Adjust
Adjust
Adjust
Adjust
Repair
8. Engine emits
too much
smoke.
Black smoke (1) Injection timing is too early.
(2) Intake air volume is insufficient.
(3) The amount of injection is uneven.
(4) Injection from nozzle is improper. Adjust
Inspect and repair
Adjust
Repair or replace
White smoke (1) Injection timing is too late.
(2) Water is mixed in fuel.
(3) Lube oil comes into the combustion chamber.
(4) Engine is over cooled.
Adjust
Inspect fuel system,
and clean
Repair
Inspect
Fault Cause Remedy