ZeeKee 593959 Recoil Pull Starter for Yard Machines 21'' 140cc 550EX Lawn Mower Compatible with Briggs Stratton 140cc 550 EX 591139 593961 590588 Cover Diameter 6 3/4 inches

What It Is

The ZeeKee 593959 Recoil Pull Starter is an aftermarket replacement pull-start assembly designed for Yard Machines 21-inch 140cc 550EX lawn mowers, and it also fits select Briggs & Stratton 140cc 550 EX engines. It’s the part you pull to start the engine—when the original rope snaps or the recoil mechanism fails, this unit replaces the entire starter housing and spring.

Fitment & Compatibility

Before buying, verify these three things:

• Engine model: Confirmed fit for Briggs & Stratton 140cc 550 EX engines using OEM part numbers 591139, 593961, or 590588. Also works on Yard Machines 21" mowers with the 550EX engine.
• Cover diameter: The starter cover is 6 3/4 inches across. Measure your old cover’s outer diameter—if it matches, you’re good. If your engine uses a different size (e.g., 7-inch or 5-inch), this won’t fit.
• Mounting holes: The bolt pattern is standard for this engine series, but check that the three mounting holes align with your engine’s flywheel shroud. No modification needed on compatible models.

Not a universal fit—double-check your engine’s model number (stamped near the spark plug or under the air filter cover). This is an aftermarket part, not OEM Briggs & Stratton.

Key Things to Know

• Quality: Generally solid build for the price—metal housing, nylon rope, and a spring that holds up well in residential use. Some users report the rope is slightly shorter than OEM, but still functional.
• Installation difficulty: Easy for DIYers. Remove one bolt (usually a 5/16" or 8mm) holding the old starter, pull the old unit off, and bolt the new one on. Takes 10–15 minutes. No special tools required.
• Common gotcha: The spring tension may need adjustment after installation. If the rope doesn’t retract fully, rewind it by turning the pulley clockwise a few turns before securing the rope.
• Rope replacement: You can’t just replace the rope on this unit—the entire assembly is sealed. If the rope breaks again, you’ll need a new starter.

Should You Buy It

Yes, if you have a compatible Yard Machines or Briggs & Stratton 140cc 550 EX engine and your original starter is broken or worn out. It’s a cheap, easy fix that avoids buying a whole new mower. Skip it if your engine uses a different cover diameter or if you’re looking for an OEM part—this is a reliable aftermarket alternative, not a factory replacement.