How to Read a Marathon Pool Motor Label

WRITTEN BY:  Inyo Pools

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When replacing a dead Marathon pool pump motor the motor label can appear to be jumble of numbers and letters. This "How to" will guide you through which information is useful in your replacement pump motor search. We also provide tips on essential parts that should be replaced when installing a new pump motor.

Step by Step


Step 1

Tools you may need: 1. A cloth and cleaning solution, this is needed to remove any dirt or grime causing your pump motor label to be unreadable 2. A Shaft Seal or GOKIT when replacing your motor. Working seals and gaskets are vital to the health of your pool pump. A malfunctioning shaft seal will cause water from the pump to leak into your electrical motor causing it to fail prematurely. A GOKIT includes the complete set of your pumps gaskets and O-rings, including the shaft seal.

Step 2

When you're searching for a Marathon replacement pool motor the key pieces of information you can have are the Model (MOD) or Catalog (CAT) number. These numbers exactly identify the motor and ratings, when entered into Inyo's product search engine a drop-in replacement can be found. A model number for a Marathon Pool Motor is listed on the left hand corner of the label. This number has a distinct format which will begin with a "5KC" with eight to ten interchanging numbers and letters following. For example, 5KC38SN6084X, as is this number can be searched in our product catalog. The Catalog Number (CAT) is listed on the left hand corner of the motor. Its format will begin with a "C" with four digits after, for example C1245. If the model number not available use this CAT number to search your pool pump motor match.

Step 3

A search of the numbers described above will provide an exact match with a simple search but sometimes those numbers may be scratched off or not listed. In cases such as these you will need use other ratings on your label to search for a proper replacement. These ratings are the Horsepower (HP), Service Factor (SF), and Frame (FR). Also we suggest you read the guide How to identify your Pool Motor without the label .

Step 4

The Horsepower (HP) rating is the power output of your motor, like a car engine, more Hp determines more flow. This number is important to match because any change in HP may cause you to change impeller and/or diffuser.

Step 5

The Service Factor (SF) of a motor helps you determine the "Total HP" of its output. This is done by multiplying the horsepower by the service factor the product is the true HP of your motor. There are two separate categories of service factor ratings, Up Rated and Full Rated. An SF listed at 1.27 and below is considered Up Rated, anything above is Full Rated. When considering a motor replacement makes sure the service factor matches or there could be an incompatibility with your pump.


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InyoPools Product Specialist Dennis R.  Posted: 3/20/2017 

CHARLIE - If you are asking if these 2 bolts can be replaced, I don't have the specific part number for these bolts but here is a link to our Thru Bolts page. Match to the length and diameter size. If you don’t know the diameter, take the bolt into a hardware store and they should be able to match it to their sockets. Paul – You should see a part number on the underside of the cover. Put that into our customer page and it will point you to a parts list for this pump.

CHARLIE  Posted: 3/18/2017 

I have a model # 5kc39un2522dx cat. no c1306 1 hp 3450 rpm ...I am trying to get to the bearings. On the square end I removed 4 long bolts and nuts. There are 2 others, on the square end near the shaft. I know they will brake, that should be alright?

InyoPools Product Specialist Dennis R.  Posted: 2/27/2017 

Gerardo - If your 5KCR39SN2823AX motor is single speed (SS), your SS replacement motor is UST1152. If you have a variable speed (VS) motor or would like to convert your current SS motor to VS, replace your motor with an ECM16CU motor. In either case, remember to replace the motor shaft seal. We would need to know the pump model that this motor is going into to specify the tight shaft seal.

Gerardo  Posted: 2/27/2017 

Cannot find model 5KCR39SN2823AX, what would be an alternative?

InyoPools Product Specialist Dennis R.  Posted: 10/24/2016 

Mike - It looks like your motor 5KC38SN6084AK matches to a USQ1102 [5KC38SN6084X]. Note: Marathon motors were bought out some years ago.

Mike  Posted: 10/22/2016 

Motor Mod.

Mike  Posted: 10/22/2016 

Sn: 09j189
Is there a substitute number for it?
This is what I can read, very faded.

InyoPools Product Specialist Dennis R.  Posted: 10/12/2015 

Aj777 - Your part #, 5KC36MN2533BX, references the motor on your pump. The replacement motor for that part # is A.O. Smith 3/4 HP Square Flange Up Rate Motor (USQ1072). Your motor's part number 5KC36MN2533BX, is included in the list of alternate part #s.

AJ777  Posted: 10/12/2015 

I am looking for a Marathon pool pump. 5KC36MN2533BX CAT.C1244

Marcia  Posted: 8/25/2015 

A wonderful guide to use as a helpful tool before attempting to locate a new motor. Good tips, well written in understandable terms. Identifies what is needed before undertaking the project of locating and replacing a pool pump motor.

InyoPools Product Specialist Dennis R.  Posted: 6/2/2015 

Dave - This should be the replacement motor for C1247 - A.O. Smith 2 H.P. Square Flange Up Rate Motor (USQ1202). Check that the motor specs match those on your old motor label.

Dave  Posted: 6/2/2015 

Looking for pool motor replacement. 2 HP, cat #c1247