I have a craftman air compressor,5.5 hp.30 gal.tank,7 or 8 years old not used much,but always worked good until yesterday now motor makes 4 or 5 revolutions and kicks out breakers cooling fan and motor turn freely. Thanks

Weak starting capacitor on the electric motor.

For warm climate, use 30wt non detergent oil (lowest price $3). Med priced oil ($5), use compessor oil sold at Lowes or any major center store including Wal Mart. Compressor oil is special blend for higher temperature range (continuous use). High price oil, synthetic compressor oil works for heavy duty use under severe conditions (also sold at major lumber centers, cost about $8~18).
For lite duty, any oil that you have handy will work fine (check oil before every use). Good luck

1) Check that it is not already at full pressure
2) Check that you have power coming in to the switch (20 year old power cord)
3) Bypass the switch and, briefly, plug it in.
4) Look for a fuse or breaker.
5) With the motor leads disconnected from the switch, check that you have resistance across the motor (0 ohms would be bad).

If you are not comfortable doing any part of this, don't. Check with friends & neighbors for a reputable local appliance repair company.

Im not sure if iv;e got this straightYou had a 242running on 120 v driven by 5 hp dayton motor You have a new 80 gal tank with a bad 7.5 v motor and want to put the 5 v motor on it What was the size of the old tank if it was 60 or more you should be ok the 5 hp will have to work harder as long as you can make it fit you may want to consider droping down the blow out valve presssre spec 10 to 15 lbs depending on the size of the old tank

1. Are you sure the motor is wired for the correct voltage? If you have 230V 3PH,Make sure that you do have 3 hot legs. you should have L1-1+7, L2-2+8, L3-3+9 and 4+5+6 connected together. If it is wired for 480V it will not have enough torque. Check rotation. There should be an arrow on pully (large one on compressor)

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.

sounds like the regulator is faulty, normal running air should reach 110 psi, this will allow you to run tools...

You probably have a restriction in the regulator. You may be able to disassemble and clean it but you'll have to relieve the tank.

Same as all my 220v compressor motors. Contacts make and then enable (maximum) start-up current inside motor (brushes). Only flashes for a moment....startling yet normal. Hope this helps!

it could take up to 30 minutes from zero pressure