compressor starting to act up.

[ko3579]

my air compressor has recently started making a jerking noise just as it shuts off from running, It doesnt do it evertime but its starting to be more frequently. It sounds almost as if it locks up then frees itself or something, its kind of hard to explain. Was wondering if any of you guys have had this problem before, or even know what the problem is. Ive been thinking about replacing the electric motor and the pump engine. Its a Blackmax compressor with a 80 gallon tank and a 5hp motor.

[Restoguy]

Check to be sure that the pully is securely fastened to the shaft. When the set screw gets loose, all kinds of funny things happen.