Boatlift motor won't startup

[Oef]

I have a small electric motor that drives a boat lift. The motor worked fine until recently. Now, when I switch the motor on, it just hums. If I give the pulley a turn, it starts and it works fine...until I stop it, then the same thing happens when I try to restart it. Also, when it hums, the light bulb that is on the same circuit dims. It had "dirt dobber nests" in it, which I have tried to blow out with air. It is fairly clean now, but the problem is still there. Any suggestions?

Motor Info:
Magnetek Century Electric
HP: 3/4
RPM: 1725
HZ: 60
VOLTS: 115
AMPS: 10.2
PH: 1 SF 1.00
FR: J56
TYPE: CSS

 

[itsmoked]

Yes! If this is a single phase motor it has a centrifical switch inside that connects up a start winding whenever the motor isn't spinning about three quarters or more of full speed.

The contacts in that switch are probably fouled. Or the switch is jammed open.

Remove ALL power and open up the motor. Check continuity and operation of this switch.

 

[edison123]

May be it has a blown capacitor ?

 

[itsmoked]

Good point too! Bad start cap.

 

[Oef]

Thanks for responding so quickly. I opened up the motor to clean it out, but I'm not sure what I'm looking for.

Is the start capacitor something that I can replace or test?
Where is it located?

Also, where is the centrifical switch located?

 

[jraef]

The switch will be on the end opposte the shaft (unless it's a dual shaft motor, I didn't look it up). It may have another cover over it inside that you must remove to see it.
Here is what it looks like. Motor Service Link If you had insects nesting inside, they may have jammed up that switch.

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