131-4509 125-2532 Mower Idler Pulley & 120-3335 Belt Kit for Toro 30" Deck TimeMaster Tractors 126-0316, 131-4506, 131-4529, 121-5763, Fits Model 20199, 20200, 20975, 20977, 20978, 21199, 21200.etc.

What It Is

This kit bundles an idler pulley (part 131-4509 / 125-2532) and a drive belt (120-3335) for Toro TimeMaster 30-inch deck mowers. It keeps the blade drive system tensioned and spinning smoothly, replacing worn parts that cause belt slipping, vibration, or deck disengagement.

Fitment & Compatibility

Before buying, confirm your mower has a 30-inch TimeMaster deck (not the 22- or 24-inch models). This kit fits Toro models 20199, 20200, 20975, 20977, 20978, 21199, and 21200, plus decks using pulleys 126-0316, 131-4506, 131-4529, and 121-5763. Check your existing pulley’s outside diameter – the replacement is 3.5 inches with a 5/8-inch bore and sealed ball bearing. The belt is 120-3335 (OEM equivalent), 1/2-inch wide by roughly 100 inches long. If your original pulley has a different bore size or belt width, this kit won’t fit. Always verify your mower’s model number under the seat or on the frame.

Key Things to Know

• Quality: The pulley is steel with a sealed bearing – durable for residential and light commercial use. The belt is reinforced rubber, not Kevlar, so expect 2-3 seasons with proper tension.
• Installation: Moderate difficulty. You’ll need a socket set and a belt tool (or a long screwdriver) to release tension from the spring-loaded idler arm. Budget 30-45 minutes.
• Common gotcha: The idler pulley’s shoulder bolt can be seized from corrosion. Apply penetrating oil before removal. Also, the belt routing is specific – check your deck diagram or Toro’s manual; routing wrong causes rapid belt wear.
• Not universal: This is for Toro TimeMaster only. Will not fit standard Toro 22-inch Recycler or Super Recycler decks.

Should You Buy It

If your Toro TimeMaster 30-inch deck is squealing, vibrating, or leaving uncut strips, this kit is a cost-effective fix. It’s a direct OEM replacement at a better price than buying pulley and belt separately. Skip it if your deck is non-Toro or a different size – fitment is strict. For a straightforward refresh of a common wear point, this is a solid buy.