Flat Idler Pulley for AYP Husqvarna 539112196 539131148 539132728 589766101 589766102 Fits EZ 4220 EZ4824 EZ 5225 EZ 5226 Poulan Pro 461ZX 46" Zero-Turn mowers

What It Is

The flat idler pulley (OEM #539112196 / 539131148 / 539132728) is a non-spring-loaded guide pulley that routes and tensions the deck belt on select AYP, Husqvarna, and Poulan Pro zero-turn mowers. It’s used on 46″ and 48″ fabricated decks, typically on EZ and ZX series machines.

Fitment & Compatibility

Before buying, confirm your mower’s deck size and model. This pulley fits:

• Husqvarna: EZ 4220, EZ4824, EZ 5225, EZ 5226 (and other EZ/YZ models with 46″ or 48″ decks)
• Poulan Pro: 461ZX, 4619ZX, 4620ZX, 4626ZX (46″ deck)
• Cross-references: Also replaces #589766101, #589766102

What to check:

• Deck belt length (typically 120″–128″ for these models)
• Pulley outer diameter: 4.0″ (measured across the flat face)
• Bore size: 1/2″ (standard for AYP spindles)
• Bearing type: Sealed ball bearing (integrated, not serviceable)

Measure your old pulley’s diameter and bore with a caliper—aftermarket versions may vary by 0.1″. Verify your deck’s idler arm uses a flat (not grooved) pulley. If your mower uses a grooved idler, this part won’t fit.

Key Things to Know

• Quality: OEM Husqvarna/AYP part—good bearings, consistent dimensions. Aftermarket copies (e.g., Stens, Oregon) are cheaper but may have shorter bearing life.
• Installation: Easy (10–15 minutes). Remove belt, unbolt old pulley, bolt on new one. Use a 1/2″ socket. No special tools needed.
• Common gotcha: The bolt can be tight from rust—spray with penetrating oil before removal. Don’t overtighten the new bolt (torque to ~25 ft-lb). A warped or wobbling pulley indicates a bent idler arm, not a bad pulley.
• Check belt tension: If the belt still slips after replacement, the idler arm spring may be weak or the belt is worn.

Should You Buy It

Buy it if your Husqvarna or Poulan Pro zero-turn’s deck belt is slipping, squealing, or throwing, and the old pulley feels gritty or has visible flat spots. At $12.68 with a strong rating, it’s a reliable OEM fix for a common wear part. Skip it if your mower has a grooved idler or a smaller 42″ deck—fitment won’t match.