My compresspr stop pumping air into the tank, but the motor and compressor ar running found a piece of blue material about half the size pf a dime between the reed plates .

Electric motors seem to turn around 1125 rpm or 3600 rpm. The pulley size on the motor and pump must be adjusted to achieve the desired result without overheating /loading the motor. I have seen pumps turning from 800 to 1200 rpm using different pulley size on motor, motor hp and motor rpm. Some brands will turn same pump from 1200 to 3600 rpm depending on if was electric or gas motor. This will certainly shorten the life of the pump but will most likely work. Most turn an average of 1200 rpm for good balance of long life and good supply of air. Pump rpm is usually limited to the power of the motor. Cost effective match of 1.5 hp motor will turn pump about 1000 - 1200 rpm for about 5cfm. Rol Air 2hp motor turns 2 cyl pump about 1100 rpm for 10 cfm. Good luck

If it is a head gasket leak and no gasket available. I would make one. You will need to buy a piece of high temp gasket material like garlock and it needs to be the correct thickness as the old material/gasket. Remove the old gasket and trace out a new one and cut it out. Or you can locate 2 bolt holes one on each side of the head put 2 holes in the material and use the bolts to hold it in place. Use a small hammer and tap around the edges. If done correctly while tapping it will cut the material. you can do bolt holes, the complete gasket like this.

The motor will run hot/overload if wrong size or too long cord is used. Also if pressure is set too high (most set at 125 ~ 135 at shut-off). In-tank checkvalve will also have effect on motor by loading the compressor at start-up. Easy test. Run compessor till you have over 100lbs in tank then unplug from power. At this point try to turn the motor /pump by hand, it should turn rather/very easily (this test is hard to do if the motor /pump is completely enclosed, you need to be able to turn the pump even if by truning the fan blade). If it does not turn easily let all the air pressure out of tank and then try to turn by hand. If it turns easily with tank empty try one more test. Run compessor till the pressure switch turns it off. Then unplug machine and turn compessor again by hand, should be easy. If not easy then unloader / checkvalve not working. The checkvalve could be leaking air back from the tank loading the pump. Replace parts as needed.

You did not list model number, however if you have oilless type check the cylinder/piston by manually turning crank until piston is at top and examine cylinder for wear or scratches. If worn replace cylinder kit for full pressure. If ok check reed valves /valve plate for wear or broken reeds. If oil bath type, problem is usually air leak or reed valves / valve plate. As a general rule, you can keep track of wear by noting how many minutes it takes to fill the tank to cut-out. As the compressor wears it will take increasingly longer to fill. When new, and depending on tank size/ hp, most compessors fill within 2 ~ 5 min. Good luck

You suspect this unit as being a two stage because of the unusually high cut off pressure. It is a single stage and the motor really has a difficult task and is being pushed to the limits. to reach this pressure. We usually reset the pressure to lower setting ~~ say around 140. Your pump probably has a leaking intank check valve (brass fitting at tank) or leaking valve plate in pump. Simple tests : with pressure in tank unplug compressor from outlet and listens for air leak around pressure switch. As you unplug the running compressor from outlet you should hear air leaking from pressure switch for just a moment as air is let out of airline from pump to tank. If air leaks out till zero pressure then change the valve. If tank holds pressure then valve probably ok. Next test, with no air in tank and air filter removed, plug in compressor and feel intake port for strong suction. If the valve plate is bad, suction will decrease as pressure neers the 120 mark till the point of feeling that air is actually blowing out of intake. With good valve plate there will be strong suction untill unit reaches set pressure. If valve plate is bad also change the cylinder and piston ring. Good luck with your repair.

You left that question rather vague. Are you asking what material? or What size? I normally would run one size larger pipe size than the outlet on the tank, unless the distance is great. You would connect to the tank outlet which is usually 1/2 way up the side of the tank. Use only black iron or copper pipe, plastic pipe is not strong enough for compressed air. There is some plasic tubing rated for air, but that looks sloppy and isn't inexpensive eitehr. Also put a "FRL" between the compressor and piping (FRL=filter regulator lubricator).

Make sure the tank drain on the bottom of the tank is shut off if there is one.
It should not take more than three or four minutes to fill a small pancake tank.
You hear any hissing noises while the pump is running? If so, there's an air leak, see if you can stop them somehow.
If the above does not answer, return unit for refund or exchange.

Your comperssor is oilless type and suffers from short cylinder / piston life. When the compressor no longer reaches cycle pressure the cylinder / piston should be replaced. These parts are available at www.chpower.com I believe that the part number is wl210300aj. Not expensive, enjoy.

Assuming that the motor is factory matched to pump, it should be powerful enough to turn the pump. Most problems with motors are related to pressure switch and/or capacitor. The pressure switch could have burned contacts causing low amps to reach the motor. The capacitor should test at least 90% of rated value printed on capacitor. Some volt meters have capacitor check setting. Also this motor at 5 hp must draw lots of amps. The outlet should be rated at least 20 amps and plug the compressor directly into oulet without an extension cord. \
Secondary problem is the in-tank check valve. The check valve should hold in tank pressure without leaking back to the head of the pump. If check valve leaks, replace it with any brand of same thread size. enjoy

Tank size only becomes a factor for one reason – A larger tank for air. A compressor will run until the pressure in the tank builds to its high-pressure point. Obviously, the bigger the tank, the longer it takes to consume the compressed air. However, the downfall is that once the air is depleted, it takes a lot longer for the air tank to refill with pressurized air. I would only go with the bigger tank if I am concerned about the motor starting and stopping too often, or if I know that I will need a constant flow of air in longer intervals. You have a choice between a larger tank and a constant-run unit.