LiftMaster K17-50098 2-1/2 Inch Motor Pulley for Gate Operators
The LiftMaster K17-50098 is a replacement motor pulley for select LiftMaster slide and swing gate operators. It is commonly described as a 2-1/2 inch outside diameter pulley with a 1/2 inch bore and is also referenced by the older Q025 service number. The pulley mounts at the motor side of the drive system and works with the belt to transfer motor rotation into the operator drivetrain. Pulley wear, bore damage, set screw issues, or belt tracking problems can cause noise, slipping, uneven belt wear, or unreliable gate movement. Since pulley dimensions can look close across different operators, the Q025 reference, bore size, outside diameter, and parts diagram should all match before ordering.
This part should be selected by matching the original component, the operator model, and the parts diagram. LiftMaster and Elite gate and commercial door operator parts often share similar shapes, numbers, and applications, but small differences in belt length, pulley dimensions, board generation, harness layout, or accessory input requirements can determine whether the part will work correctly. For that reason, the compatibility section below is written broadly where supported but still uses careful fitment language where model generation or configuration can change the correct part.
What This Part Does
This pulley is part of the mechanical drive system. It supports belt alignment and power transfer between the motor and operator drivetrain. A damaged pulley can create belt tracking problems, squealing, wobble, and premature belt wear.
Compatible With
The LiftMaster K17-50098 2-1/2 Inch Motor Pulley for Gate Operators is commonly associated with the following LiftMaster or Elite applications. Compatibility should be confirmed by the exact operator model, original part number, and parts diagram, especially when the equipment has been repaired, updated, or modified in the field.
Common Compatible Models and Applications
- Select LiftMaster CSW200UL swing gate operator configurations
- Select LiftMaster 200UL8 swing gate operator configurations
- Select LiftMaster CSW200U / CSW200 gate operator drive assemblies when Q025 is specified
- Select LiftMaster slide gate operators when the parts diagram calls for K17-50098 / Q025
- Commercial and perimeter access gate operators using a 2-1/2 inch OD, 1/2 inch bore motor pulley
Important Compatibility Notes
- Use the exact original part number or confirmed related service number whenever possible.
- Do not rely on appearance alone; similar LiftMaster parts may not interchange.
- Check the operator model, production generation, horsepower or voltage where applicable, and parts diagram.
- For gate operators, inspect the gate movement and safety devices before returning the operator to service.
- For electronic boards, verify harness layout, accessory wiring, monitored safety inputs, and diagnostic behavior before installation.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Replacement Motor Pulley |
| Part Number | K17-50098 |
| Application | Motor pulley replacement for select LiftMaster slide and swing gate operators |
| Compatible Operator Type | Select LiftMaster slide and swing gate operators using the Q025 / 2-1/2 inch OD, 1/2 inch bore pulley |
| Also Known As | K17-50098, 17-50098, Q025, LiftMaster Q025, 2-1/2 inch OD pulley, 1/2 inch bore pulley |
| Notes | Verify outside diameter, bore size, key/set-screw arrangement, belt style, and operator model. Similar pulleys may not align with the belt path or motor shaft correctly. |
Also Known As / Related Part Numbers
The following numbers and search variations are commonly associated with this item. Some are exact service numbers while others are related catalog formats, older labels, or common search terms. Match the part by the operator parts diagram before treating any related number as a direct replacement.
- K17-50098
- 17-50098
- Q025
- LiftMaster Q025
- 2-1/2 inch OD pulley
- 1/2 inch bore pulley
- motor pulley Q025
- K17-50098 motor pulley
Technician Note
Verify outside diameter, bore size, key/set-screw arrangement, belt style, and operator model. Similar pulleys may not align with the belt path or motor shaft correctly. Inspect related parts before installation. Belt and pulley failures can be caused by alignment, tension, worn bearings, gearbox load, or a gate/door that is binding. Control-board failures can be caused by moisture, insects, surge damage, shorted wiring, failed accessories, or incorrect safety-device wiring.
Before Ordering, Confirm
- Original part number or old service number on the part being replaced
- Operator model number and production generation
- Parts diagram for the exact operator configuration
- Belt length, pulley size, board generation, or harness layout where applicable
- Voltage, horsepower, learn button, safety-device, or accessory requirements where applicable
- No related mechanical binding, wiring short, surge damage, or accessory failure remains unresolved
Professional Advisory
Gate operators and commercial door operators should be serviced with power disconnected and with the moving gate or door secured as needed. Do not bypass monitored safety devices, photo eyes, edges, loop inputs, or entrapment protection to make a system run. After replacement, test the operator, limits, travel, safety devices, accessories, and manual release according to the equipment requirements. High-voltage, heavy-gate, or unsafe operating conditions should be handled by a qualified gate or garage door technician.
Important Ordering Warnings
- Similar-looking LiftMaster parts may not be interchangeable.
- A different belt length, pulley bore, or board generation can cause installation failure or operator damage.
- Do not install electronic boards into equipment with unresolved wiring shorts, water damage, or surge damage.
- Do not use a replacement part to work around a missing or failed safety device.
- If the existing product title, old part number, and parts diagram disagree, verify the operator before publishing or ordering.
Questions & Answers
What is the LiftMaster K17-50098 used for?
The LiftMaster K17-50098 is a replacement pulley used in Select LiftMaster slide and swing gate operators using the Q025 / 2-1/2 inch OD, 1/2 inch bore pulley.
What dimensions should be checked before ordering?
Confirm the pulley outside diameter, bore size, belt type, shaft fit, and any set screw or keyway details before replacing the part.
Can a worn pulley damage a new belt?
Yes. A worn, misaligned, loose, or damaged pulley can cause belt tracking problems, slipping, noise, and premature belt wear.
Is this pulley universal for all LiftMaster operators?
No. LiftMaster uses many pulley sizes and bore configurations. This part should only be used where the operator parts diagram calls for the same pulley number or dimensions.
What should be checked after installing the pulley?
Check belt alignment, belt tension, pulley set screw security, shaft condition, and safe operator travel before returning the system to normal use.
