917-05121 PTO Clutch | Replaces 717-05121 & Warner 5217-77

Overview

This aftermarket 917-05121 electric PTO clutch replaces 717-05121 on select Cub Cadet, Troy-Bilt, MTD, Bolens, Huskee, White Outdoor, and Craftsman mower applications.

Common applications include select Cub Cadet RZT-L42 and RZT-S42 zero-turn mowers and Troy-Bilt Mustang 42 XP models from the 2013–2014 production years. Fitment depends on the mower’s model, serial number, and original clutch number.

This clutch has an approximately 5.95-inch pulley, a 1-inch crankshaft bore, counterclockwise rotation, and an A/B-section V-belt pulley. Compare all specifications, the electrical connector, and the anti-rotation configuration with your original clutch before ordering.

Key Features

• Aftermarket electric PTO clutch replacement
• Crankshaft Bore: 1 inch
• Pulley Diameter: approximately 5.95 inches
• Rotation: counterclockwise (CCW)
• Belt Compatibility: A/B-section V-belts, commonly sold as 1/2-inch and 5/8-inch mower belts; use the OEM-specified belt for your mower
• Integrated electromagnetic coil and electrical connector
• Fully assembled and ready to install

Compatible Brands & Model Series

Verified application paths for the 717-05121 / 917-05121 clutch family include:

• Cub Cadet: RZT-L42, 2013–2014 models
• Cub Cadet: RZT-S42, 2013–2014 models
• Troy-Bilt: Mustang 42 XP, 2013–2014 models
• MTD / Bolens / Huskee / White Outdoor: select Z6000, ZT42, and ZT-L42 applications
• Craftsman: select applications originally equipped with 717-05121 or 917-05121

Important: Model names may cover multiple production years and clutch configurations. Confirm the part number on your original clutch before ordering.

Replaces OEM Part Numbers

• Cub Cadet / MTD / Troy-Bilt: 717-05121, 717-05121A, 917-05121, 917-05121A
• Bolens / Craftsman / Huskee / White Outdoor: 717-05121, 917-05121

Common no-dash searches: 71705121, 71705121A, 91705121, 91705121A

Aftermarket Cross-Reference Numbers

• Warner: 5217-77, 5217-90

Common no-dash searches: 521777, 521790

Fitment Check

Before ordering, compare this replacement with your original PTO clutch and confirm:

• The original clutch number matches one of the numbers listed above
• The crankshaft bore measures 1 inch
• The pulley diameter is approximately 5.95 inches
• The rotation direction matches the original clutch
• The pulley accepts the correct mower-deck belt
• The electrical connector matches the mower wiring harness
• The anti-rotation bracket or clutch stop aligns correctly

What’s Included

• Complete electric PTO clutch assembly
• Integrated pulley
• Pre-installed bearing assembly
• Electromagnetic coil
• Integrated electrical connector

Note: Mounting bolt, washer, spacer, and mower-side anti-rotation hardware are not included unless specifically shown in the product photos. Inspect and reuse the original hardware where appropriate.

Why Buy From PTO Direct USA?

• Fast USA shipping
• Fitment Guarantee
• Fitment support before and after purchase
• Premium product images for easy identification
• Trusted replacement supplier for homeowners and mowing professionals

Need a different fitment? Browse the full electric PTO clutch catalog to see all available replacement options.