At FOUJI we take utmost care in all aspect while manufacturing compressors however for longevity and proper functioning of compressors, instructions given must be followed.


  • Tension of the V-belt to be checked up every week.
  • Starter’s Amp. calibration should agree to the Electric motor.
  • Connect the Electric motor to the required mains properly and observe safety measures.
  • Electric motor (rotation) must run anticlockwise as per arrow direction.
  • Adjust the Automatic pressure switch and safety valve equally and to the required pressure.
  • Check up the firmness of the fasteners (bolts and nuts) periodically to avoid loosening and vibration.
  • Do not run the compressor without oil up to the required level.


  • Use lubricating oil D. T. E. Oil heavy medium or D. T. E. Oil extra heavy duty of standard Vacuum Co. Oil as good as those mentioned above or oils which set free few carbon are suitable. But we have to change thickness of oil we use according to room temperature or season. For instance in summer, it is better to use thicker oil. When it is hard to get ideal lubrication oil, we often use automobile oil as substitute, namely, in summer No. 30 auto-oil and in winter No. 40. The quantity of oil in crank-case is proper when oil level goes up to the half point of the gauge. When oil becomes dirty, strain it or change it with new one.
  • Adjust stretch of belt. When two belts are used, stretch of both must be same. When stretch of two belts are not same, overload on electric motor will occur.
  • Direction of revolution must follow arrow direction on cylinder pulley. When it turns in the opposite direction, feathers of pulley will not work for cooling air.
  • Disassemble suction filter frequently, and take care that no dust enters the cylinder.
  • Disassembling & Cleaning must be done carefully; especially dust must be removed completely. Careless or rough “disassembling & cleaning” makes machine worse.
  • If your hear queer noise on machine, stop running the machine at once examine obstacles and repair it.
  • Look at pressure gauge, as less pressure goes up over a certain kgs.
  • Once in two or three days loosen drain cock which is on the lower part of tank and run machine to drain, give a little pressure in tank. Keep carefully the certificate for proof-pressure of tank.
  • Examine if pressure gauge has any trouble or not. Sometimes you believe that pressure doesn’t go up because of some trouble on machine while not knowing breakdown of gauge.
  • Keep machine level proper when in use.
  • Fixed machine gives less vibration when in drive.
  • When belt becomes too long, pull motor back and make belt tight.
  • Pay attention if voltage drops. Sometimes motor causes trouble when you run machine inspite of voltage – drop.


We assure to replace, free of charge, within six months from date of sale, any “Fouji” air compressor which in its judgment has failed because of defective material or workmanship, provided it has been shown to have been properly mounted. Properly maintained and not subjected to abuse in operation or handling. Such compressor must be returned to the factory charges prepaid and with complete information as to service. We assume no responsibility for contingent or consequential damage in any event.

This guarantee is in lieu of all warranties either expressed or implied.


(A) Queer noise is heard in case.
  • Key of pulley loosen.
  • Bolts and nuts on piston-rods loosen.
  • Rod wears away.
  • Crank-shaft bearing wears away.
  • Suction valve or exhaust valve breaks.
(B) Pressure doesn’t go up in case.
  • Head gasket worn seat.
  • Piping in air tank or other circulation pipe has air-leaking.
  • Valve on cylinder-head worn away extremely and plate is not lose together with seat.
  • Safety valve leaking (owing to trouble of safety valve)
  • Suction or exhaust valve is broken.
(C) Sudden stop of running machine in case.
  • Lubrication oil doesn’t circulate completely.
  • Trouble of worn parts.
  • Extreme voltage drop.


(A) Action of automatic switch

Compressed air in compressor enters air tank through subsidiary copper tube (1) and catch valve. When air pressure in air tank goes up to a certain kgs. Compressed air in air tank goes through copper tube and pushes spring in automatic switch. The switch works on lever, which cuts off electric current. Rotation of motor stops, after the compressor stops to move. At the same time by work of lever of automatic switch release – valve is opened and air in subsidiary tank and in copper tube (1) is discharge (if relief valve is there).

When air pressure in air tank goes down, pressure on switch falls, and the lever in automatic switch comes back to former state by action of spring. The electric current which was cut off is connected again and the motor starts to move and at the same time release valve will be closed.

(B) Object

It is not desirable to run air-cooling type compressor for long time with high pressure. When enough pressure is obtained it is necessary to stop compressor. This switch is used when compressor is not used continually to make it move all time.

(C) Starting

When compressor stops to work by action of automaic switch, release – valve opens at the same time. There is no compressed air in subsidiary tank. In this case, when motor begins to work, it does normal movement, but when you want to run comressor again after you cut off main switch you have to open drain cock and discharge compressor air in subsidiary tank.

Unless you don’t discharge air of tank, over-land on motor will occur. Sometimes motor will burn up. There is no trouble when no pressure is in tank.

(D) Regulation of Pressure

To change limit of desired pressure, look at the back side of cover of automatic switch, you will find details of direction on it. Turn screw to the left or right as you like to regulate.

(E) Obstacles

While operating compressor, if rise of pressure is slow, air is leaking through air-cock under subsidiary tank or valve attached on automatic switch. While comressor is stopping, pressure goes down suddenly there must be dust in non return valve. For air in tank goes out from this valve through subsidiary air tank and copper tube.

(F) Attention

Compressor with automatic switch stops movement when pressure goes up to a certain degree. So it is unnecessary to cut off main switch while you take a rest. Cutting off main switch sometimes becomes cause of trouble of motor We hope you pay attention about the fact. After long time, stopping of machine or after you finish work if you cut off main switch, you have to discharge pressure in subsidiary tank. In case, you want to start to run the machine again as mentioned above and it is desirable to open cock under subsidiary tank and drain occasionally.