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Cause and maintenance method of forklift engine oil circuit fault

Publisher:hyder Date:2017-08-01

Cause and maintenance method of forklift engine oil circuit fault


General oil circuit fault of gasoline engine:

  • Gas mixture is too strong

1,    the phenomenon of the mixture too thick, visible valve shaft leakage of gasoline engine; lack of power, not easy to accelerate; black smoke exhaust and a "flutter and flutter" sound; spark plug too much carbon; which will automatically flameout, can not start

2,    the cause of mixed gas is too thick, the fault generally occurs in the air filter and carburetor parts. The general reason is that..:  
1)    the air filter is dirty and the filter screen is blocked    
2)    the choke is not fully opened          

3)    improper cleaning of main metering hole causes the loss of measuring hole and increases the flow rate          

4)    leakage of oil after the float is broken or the triangular needle valve is not closed tightly, causing the oil level of the float chamber to be too high    
5)    vacuum or mechanical oil saving ball valve is closed, resulting in oil leakage, increasing the main venturi oil supply.

3,    fault judgment and elimination  
1)    first, check the height of the oil level in the float chamber. In plain areas or hot areas, the oil level is highly controlled and 1~1.5mm below the mark mark is good. If the oil level is too high, it can be adjusted. Adjust to the standard, after the oil level is no longer changed, and work is normal, that is troubleshooting.          
If the oil level is not adjusted to the standard position, disconnect the carburetor and check if there is any oil in the float. If the oil is broken, the float should be welded or replaced; the float is not broken; the installation position and shape have not changed; check whether the triangular needle valve is closed or lax or hairpin; repair or replace.          
After the repair or replacement of the float or triangular needle valve, the oil level is refitted and adjusted, and the test engine, such as the restoration of the working condition, is the troubleshooting          

2)    if the oil level of the float chamber is checked as normal, the air filter can be removed to check whether the choke is fully opened in the vertical position, and that the damper shall not be released or tested in the fully open position      
3)    the opening position of the choke is normal, no hairpin phenomenon, and the test is normal without the air filter. Check that the air cleaner filter is clogged with dirt and should be cleaned or replaced with new filters.         
4)    the above procedures are normal, and the carburetor shall be dismantled and checked for further examination. First check the vacuum and mechanical fuel-efficient valve closed tight or not, closed lax, we must consider the main volume of the hole, to adjust or replace.

  • Gas mixture is too dilute

1,    the phenomenon of engine idling unstable and easy to flameout; carburetor has temper phenomenon; engine power shortage, operation is not easy to speed up; pull up the damper, the situation will be significantly improved or temporarily improved.

2,    the reason for mixed gas is too thin, in terms of its oil road, the essence is insufficient fuel, mixed gas, less gasoline. Insufficient oil supply can be divided into two parts: the oil circuit outside the carburetor and the oil circuit failure in the carburetor.     

The main cause of insufficient oil supply outside the carburetor:      
1)    the gasoline filter is blocked.         
2)    there is a blockage in the gasoline pipeline or the tubing is damaged.    
3)    the tubing joints are loose and leak.          

The main cause of insufficient oil supply in the carburetor:       
1)    the oil inlet of the carburetor is blocked, so that the oil supplied by the oil circuit can not flow smoothly into the float chamber.  
2)    the oil level in the float chamber is too low or the float is hairpin.  
3)    jam of triangle pin or other oil outlet. 
4)    main hole blockage or improper adjustment.      

In addition, the gas inlet pipe cushion leakage or carburetor base cushion cushion leak, the same will cause mixed gas too thin.

3,    fault judgment and elimination      
1)    check the oil level of the float chamber. If it meets the requirements, check whether the main hole is adjusted properly, whether the main measuring hole is blocked and repair if there is a fault.      
2)    if the oil level of the float chamber is too low, it should first determine whether the carburetor is inside the oil circuit or the carburetor outside the oil circuit, and then look for the location of the fault in sequence.
Steps are as follows:
a) Remove the carburetor inlet pipe joint, observe the oil production of the tubing, if the oil pressure is high, the flow rate is large, then the carburetor oil circuit failure.    
b) Adjust the carburetor oil surface; disassemble the carburetor, check whether the float is issued, the triangular needle valve is issued, the oil outlet is blocked, and after the above steps are found and repaired, the fault can be eliminated.          

c) Remove the carburetor inlet pipe joint, observe the oil production of the tubing, if the oil pressure is low, the flow rate is small, then the carburetor oil circuit failure.          
Should check the oil pipe, fuel tank switch, gasoline filter network, troubleshooting.  
3)    inspection shall be carried out according to the above procedures, and the leakage of the air inlet pipe or the cushion of the carburetor base shall be checked.