View Full Version : Craftsman air compressor motor problem

08-14-2011, 04:50 PM
I have this old Sears Craftsman air compressor with a 1HP GE motor( 5KC49PR98W). The motor is bad and I have been looking on-line for a new one. The motor has a special base that pivots on a rod running through the compressor's motor mounting base on top of the tank. The rocking motion is used to adjust the belt tension. The motor is no longer available through Sears and I can't find a replacement with the same kind of base.

Was the rocking base a Sears exclusive or did others use it? The only alternative seems to be a standard motor with an adjustable base added to it plus modifying the existing compressor mounting plate. It's alot of trouble and expense if an original style motor cannot be found. Might be cheaper and /or easier to have my motor rewound. Comments?


08-14-2011, 05:07 PM
There are a zillion variations on the "rocking" belt tensioning system you're talking about. They're easy to cobble up on your own -- I've probably made half a dozen of these and never spent much time. Anyhow, it might not be as much trouble and expense as it seems at first look.

On edit: You basically need a plate/plywood etc. to mount the motor, a hinge on one end, and then bolt (or thread and tap) the hinge to your existing mounting plate. You might want to have a spring mounted through bolt on the open side to maintain tension.

08-14-2011, 05:08 PM
I'd bet it's something Sears came up with so you have to buy their motor. You can make a base plate that would swing on the rod and mount the motor on that.

08-14-2011, 05:09 PM
It sounds like a Sears only type of mount, although other Mfg. have used similar setups, usually with a standard frame motor. You might be able to get away with having that one re-wound or get real lucky and get new guts that would mount into that frame. Not sure what either would cost.

08-14-2011, 05:23 PM
I've chiseled the pivot thing off of dead motors and welded it to a replacement motor. Not sure if it will work in your case, but you get the idea.

08-14-2011, 05:33 PM
I've chiseled the pivot thing off of dead motors and welded it to a replacement motor. Not sure if it will work in your case, but you get the idea.

I was just thinking that the pivot is most likey just a weird mounting plate that might go onto a normal style motor insted of its normal mounting baseplate. Failing that, your idea sounds good too. Id likey use an abrasive cutoff in an angle grinder or 3" cutoff tool depending on how delicate the job was, but to each his own.

08-14-2011, 10:18 PM
I have relieve drilled the spot welds on the mounting plate then cold chiseled to break it free,,,,,,,,,,,

08-14-2011, 10:32 PM
If you need a motor let me know. I have 1HP New tile saw motors 3450RPM with an extra recept built in (for the pump) which is handy for a light,dust collector etc, push putton reset, an on/off switch with the safety key. 5/8 shaft with keyway & key. These are the smoothest motors I've ever seen & made to keep the dust out of the motor with a strong fan. Everyone loves them. I bought 3 from a guy & liked them so much I bought all he had. Normally $100. $80 if you want one. Thanks! :D

08-14-2011, 11:17 PM
For many years Sears compressors were made by De Vilbiss. You might broaden your search there.

08-15-2011, 12:06 AM
An old air compressor will likely have a 1740 motor.

08-15-2011, 02:41 PM
Flylo, thanks for the offer, it sounds good, but I already have a new motor on the way. I'm going to try to remove the welded on pivot base from the old motor and bolt it to the feet of the new motor. If that works out, everything else will fit and I'll have my air back.


08-15-2011, 02:48 PM
I would just drill out the spot welds holding the mounts of both motors on and plug weld the old base to the new motor. There is enough mass in the motor where you should not have to worry about getting it too hot.