I have a 2 speed pump that only hummmss in both speeds. It will crank over manually. so i thought capacitor. It is a 115 v and i just happen to have another 115 v cap from a different pump that works. same prblm tho is there something else i can try or could the cap i put on it be different so it won't start the motor either

Unless the motors are the same brand and size, the caps could definentally be different. There should be uF (or MFD) ratings on the capacitors. Those are the values you will be interested in comparing. How old is the motor? It could be possible that you are dealing with a "locked rotor" situation, caused by a bad bearing. Motors don't have a lot of clearance between the rotor and the windings and if a bearing has too much play, it will actually pull the rotor against the windings when power is applied, due to the electromagnetic force. In this situation the motor can't overcome this force on startup and will just hum.

the spa is about 6 or 7 years old the original cap. has a uf # the other only has a ufd #. are the bearings pressed on or can i replace them myself if that's the problem. Ill start with new cap. the old one is corroded anyway

uF and MFD are used interchangably. Better quality motors will have sealed ball bearings which are replaceable. Lower end motors will have a sealed ball bearing in the front endbell, and a sleeve bearing in the rear. The sleeve bearing is technically replaceable, but generally not worth the effort. If you have the rear sleeve bearing and you know for sure it is your problem, save the headache and get a new motor.

I took the pump to a pro cheaper to buy a new one then parts for the old one thanks for the help