Dong Feng ZB25, Operator'S Manual

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Factory Direct Tractors
Trouble-Shooting
b. Excessive oil pressure
c. No lube oil on the rocker shaft
9.1.3 Exhaust smoking
Normally, poor atomization in the combustion chamber causes black smoke. White smoke is often an indication
to un-burnt fuel and possibly water in the cylinder. Burning engine oil in the cylinder will produce blue smoke.
a. Black Smoke
b. White smoke
c. Blue smoke
9.1.4 Engine low on power
Generally, fuel and air problems will produce abnormal combustion resulting in low power.
Possible causes
Solutions
a. Pressure regulator valve of filter is out of order. Check and adjust or replace it.
b. Oil becomes too thick at low temperature.
Replace with specified engine oil.
Possible causes
Solutions
a. Oil pressure is too low Make adjustment
b. Lubrication system is blocked
Find the problem and rectify.
Possible causes
Solutions
a. Injector nozzle slow or partially blocked. Replace or service it.
b. Overloading the engine. Adjust the gearing.
c. Incorrect fuel injection timing. Adjust it.
d. Poor valve sealing or incorrect timing. Check and adjust it.
e. Injector pump or injectors delivering fuel
unevenly.
Check and service injectors and injector pump –
specialist operation.
f. Air filter blocked.
Clean or replace as per maintenance schedule.
g. Worn cylinder liner and piston rings. Replace them with new ones.
Possible causes
Solutions
a. The third ring is fitted upside down. Refit it, with the ring face marked ‘(up)’ upward.
b. Worn piston rings and valve guides. Replace them with new ones.
c. Too much oil in the crankcase.
Drain oil to the correct level.
Possible causes
Solutions
a. Low injector pressure results. in poor
atomization with oil drops.
Check, adjust or replace the injector pump.
Cover the radiator with a cotton pad.
Check, adjust or replace the injector pump.
Cover the radiator with a cotton pad.
b. Cooling water temperature too low.
c. Water leaking in to cylinders.
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