Pre-Installed Bearings 131-4529 Idler Pulley and 120-3335 Mower Belt Kit Fit for Toro 30" Timemaster Exmark Lawn Mower, Pulley Replace 121-5765 131-4509 125-2532

What It Is

This is a combined idler pulley and mower belt kit for Toro 30" Timemaster and Exmark commercial walk-behind mowers. The pulley comes with pre-installed bearings, and the belt handles blade drive. Together, they replace worn pulleys and stretched belts to restore cutting performance.

Fitment & Compatibility

Before buying, confirm your mower has a 30-inch deck—this kit is designed specifically for Toro 30" Timemaster models (e.g., 20067, 20068, 20199) and compatible Exmark 30" units. The pulley replaces OEM part numbers 121-5765, 131-4509, and 125-2532; the belt is OEM number 120-3335. Measure your deck width to be certain, and check that your existing pulley uses a 5/8-inch bore and 3.5-inch outer diameter (the same as this replacement). If your mower has a different deck size or belt routing, this kit won’t fit.

Key Things to Know

• Pre-installed bearings save time – The pulley comes with sealed bearings already pressed in, so you don’t need a bearing puller or press. Just unbolt the old pulley and bolt this one on.
• Belt installation is straightforward – Route the belt according to your deck diagram (often printed on the top of the deck). It’s a single-belt system for blade drive—no tensioner adjustment needed beyond the spring-loaded idler.
• Check for deck damage – Worn pulley bearings often cause belt squeal or slipping. If your deck’s belt guides or tensioner arm are bent, replace those too to avoid premature belt wear.
• Aftermarket quality is solid – This is a third-party kit, not OEM Toro, but reviews indicate it matches OEM specs and lasts as long. The belt is Kevlar-reinforced; the pulley is steel with a zinc finish.

Should You Buy It

Buy this kit if your Toro 30" Timemaster or Exmark 30" mower is experiencing belt squeal, slipping, or uneven cut due to a worn idler pulley. It’s a cost-effective, drop-in replacement that avoids separate bearing purchases and works well for DIY maintenance. Skip it if you need OEM-branded parts or have a different deck size.