121-5765 Drive Belt 1/2" x 30" for Exmark 30 inch Mower Parts, Toro Timemaster 30 Drive Belt, Replaces 121-5765 Exmark 121-5765-SL V Belt

What It Is

The 121-5765 drive belt (1/2” x 30”) transfers power from the engine pulley to the blade spindle on select 30-inch walk-behind mowers. It’s designed for Toro Timemaster 30 and Exmark 30-inch mowers, driving the cutting deck.

Fitment & Compatibility

• Exact dimensions: 1/2” width, 30” outside length. Measure your old belt’s width and length (lay it flat, measure end-to-end) to confirm.
• Fits: Toro Timemaster 30 (models 20067, 20068, 20070, 20071, 20099, 20100, 20101) and Exmark 30-inch mowers (e.g., LZ30KC, LZ30KA, LZ30KD). Not for 36” or 42” decks.
• OEM vs aftermarket: This is a Toro-branded replacement, same as Exmark part 121-5765-SL. Aftermarket belts at this price are common but may wear faster.
• Check belt routing: Before buying, confirm your mower’s belt diagram. Some Timemaster models use a different belt (e.g., 121-5765 for older units; newer ones may use 121-5765-SL). Match your model number.

Key Things to Know

• Quality: Toro OEM belt is decent for residential use. Expect 1-2 seasons with regular mowing on a typical lawn. Aftermarket belts at similar price may fray sooner.
• Installation: Moderate difficulty. You’ll need to remove the deck cover, release tension from the idler pulley, and route the belt around pulleys. A belt tensioner tool helps.
• Common gotcha: The belt is directional. Arrow on the belt should point toward the engine’s rotation direction (usually clockwise when viewed from above). Installing backward causes premature wear or slipping.
• Check pulleys: If the old belt snapped or wore unevenly, inspect pulleys for damage or debris. A new belt on a bent pulley will fail quickly.

Should You Buy It

If you own a Toro Timemaster 30 or Exmark 30-inch mower and need a direct OEM replacement, this belt is a reliable, affordable choice for seasonal use. Avoid if you mow heavy commercial loads—aftermarket Kevlar-reinforced belts last longer. For the price, it’s a solid stopgap or backup.