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Boat Lift Motor
Boat Lift Motor  
I have a boat lift with a reversible electric 1 HP motor that will not start (just hums) but runs when you rotate the pulley and turn the power on at the same time.  I have been told if you clean the mud daubers and what not out of the starter assemblies that it will work fine. My concern is the age of the motor and the fact the motor might not be worth the trouble.  Do you think I could take it apart and clean it up and get it working? I would not want any parts come flying out when I try to take it apart.  I have been looking for a schematic to see if I could handle it but I have not found one.  I am one that will try to fix anything because I have nothing to loose since it doesn't work anyway.  Do you think if I use air to clean it out that it might work? Someone told me about the centrifugal starter weights might be stuck and that might be the problem. Can those be cleaned out with compressed air without remove and taking the motor apart?


You will be fine,   nothing will fly out of the motor,      the centrifugal switch has springs but they are for the weights and won't be a problem,     

Here is what you probably have,    an open start circuit,    

It should be a capacitor start motor,    if there is a metal lump on the top   that is the capacitor cover,    take the screws out, and look it over,   if it is swollen or stinks,  try replacing it first,     although a blown cap can indicate a problem with the windings    capacitors do fail by themselves,  and that is it,   

Yes any debris in the motor could have the switches hung up     

If the motor has open vents,  and you have some relatively dry air,    rotate the shaft and blow in the slots,    sometimes that is all it takes too,    

If the simple tricks don't work,  mark where the end housings are lined up on the main frame,  use a sharp punch   one punch for the shaft end     two for the opposite end

Take photos before you start,  and as you go,    

there could be an internal fan  that is on one end or the other,   it could be larger in diameter than the stator bore,   so if the rotor does not slide out easily  stop,  it might only come out one end,    that is why marking the parts as they line up is critical,   

If you have to pry on the end housing,  use two even sized pry bars or screw drivers  180 apart and attempt to walk it off the rabbet fits,

You might find rusted bearings in the housings or on the shaft journals,   if in the end housings   soak with some kind of lube for a few hours     they might pull right off the shaft and be stuck in the housing,    if so, the journal is probably undersized,   which means putting a new bearing on is a waste of time,      

If the start winding is burnt up,  you should be able to smell it or see it when you get the rotor out,     

It can be all cooked where the run winding is still fine,    

Once the rotor is out, the centrifugal switch is on the shaft,  it is a spool looking device,  make sure it does not wobble on the shaft,  if so it will get cocked and lock   not closing or opening the contacts on the stationary switch,    

The stationary switch will be bolted to the end housing,   with one to three spring arms   that have contacts on them,     you can gently pull the arm out from under the stops,  and look and see if the actual contacts are still there or thick enough to reuse,    

It takes near nothing to get between the contacts,  a bit of dust or dirt   will hold the contact[s] open,  that is why if you can blow into the motor,  if that is the problem  rotating the shaft and blowing will dislodge the debris    and it will take right off,     

But if you start finding mechanical issues and electrical issues    start looking for another motor,  but the reversing  is  tricky,      many motors are single direction,  


Also check the pulley[s] and belt[s] for wear,  drag your finger nail down the sides of the pulley inside,  and if there is a groove or ridge it needs replaced,    

But you should have no problem getting the motor apart,  just keep track of how the leads connect to the switch[s]  in case you go to replace it,     so photos are valuable   

it should have maybe a 6 pole center off, switch, and it is trick to configure,  because the ends of the start winding have to swap with the ends of the run windings,    normally 5 and 8 are start leads,      notice the voltage    is it dual or single?  Make sure if it is dual voltage you get a new one that is either dual or matches your voltage,    black and white power leads mean nothing to motors,      so no concern there,    then you will have one chassis ground wire,   important around water,    

Or you could have a levered reverse switch, also tricky to wire up  so mark each wire   both in the existing motor and if you have to  you will have a head start wiring the new one,   

There could be a "klixon" in the motor,  with a resetting button on the frame  or some just reset on their own  [I hate those,  they go bad too,  and can open the start circuit,    but the damn things will cool down and the motor will start without warning,  so if you have one  you have to check all the terminals for continuity,       

just keep in mind how the motor is wired to reverse,    so you can match it back,  this one is not the best but might be a help,   

My shop is MEAR Services Inc,  or our phone is 816-650-4030  if you get in jam,  we are always glad to try and help either way by email or on the phone,    but let me know how you get along,    

there is nothing in the motor that will be spring loaded or fall out,  but there are plenty of wires and terminals  and wires fall off,  so a photo inside along with marking each motor lead and internal lead will prevent a lot of grief later on,  

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Three phase/ AC DC single phase motors, controls, any problems or failures, motor installation, performance issues, connections. All other electric motors/gearboxes/apparatus. Specialty repair concerns, obsolete motors and solutions. Other mechanical or specialty equipment. See my profile under Home/electrical at this site


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