Flat Idler Pulley (604792 280-813 935361 933358 937151 934760 939454 937177 937821) Fits Rap tor Flip Up, Rap tor SDX, Rap tor SD, Super S 54" 60" Decks Mower

What It Is

This flat idler pulley is a replacement part for the belt tensioning system on select Scag mower decks, specifically the 54" and 60" Rap tor Flip Up, Rap tor SDX, Rap tor SD, and Super S models. It guides and tensions the drive belt to keep blades spinning at full speed.

Fitment & Compatibility

Before buying, confirm these four things:

• Deck size & model: Works on 54" and 60" decks only for the listed Scag models. Does not fit 48" or 72" decks.
• OEM cross-references: This aftermarket pulley replaces Scag OEM part numbers 604792, 280-813, 935361, 933358, 937151, 934760, 939454, 937177, and 937821.
• Measurements: Verify your original pulley has a 4.0" outer diameter, 3/4" bore, and uses a 6203 bearing (sealed). Measure yours if unsure—aftermarket specs can vary slightly.
• Belt width: Designed for standard 1/2" or 5/8" deck belts. If your deck uses a 3/8" belt, this pulley won’t work.

Key Things to Know

• Quality: Sealed 6203 bearing with metal shield—good for residential and light commercial use. Not as durable as OEM Scag bearings in heavy daily commercial cutting.
• Installation: Easy bolt-on job. Requires a 9/16" socket or wrench to remove the center bolt. No special tools needed.
• Common gotcha: The pulley is flat (not grooved). Make sure your belt rides on the flat face, not in a V-groove. If your original had a groove, this won’t work.
• Lifespan: Expect 1-2 seasons under normal use. Replace immediately if you hear squeaking or see wobble—a seized pulley can snap your belt.

Should You Buy It

Buy this if you need a budget-friendly replacement for a worn flat idler on a 54" or 60" Scag deck and don’t mind swapping it a season or two sooner than OEM. Skip it if you run a commercial mower 40+ hours a week—spend more on a genuine Scag pulley for longer service life.