Koubliztic Carburetor Kit for Bolens 21" 140cc Mower — Replacement Carb with Air Filter, Primer & Fuel Parts

Koubliztic's complete replacement carburetor kit restores reliable starting and steady throttle response for Bolens 21" 140cc lawn mowers and compatible B&S engine models.

If your Bolens, MTD or Murray mower with a 125–140cc Briggs & Stratton–series engine is running poorly, flooding, hard to start, or not delivering full power, a worn or clogged carburetor is often the culprit. This Koubliztic carburetor kit is engineered to directly replace original part numbers used on 21" 140cc models 11A-B0BL765 and 11A-020W765, providing the hardware and small parts needed for a straightforward swap and reliable on-lawn performance.

How will this carburetor improve starting and throttle control?

Installing this replacement carburetor renews fuel metering and restores the correct fuel-air mixture across idle, transition and wide-open throttle. That means faster, more consistent starts and smoother running under load.

• Factory-matching fit for Bolens 21" 140cc mower applications.
• Rebuilt fuel passages and fresh primer bulb to clear air and prime the bowl.
• Includes fuel filter and shutoff valve to prevent debris and stale fuel flow.
• Two throat clamps and hoses for a secure intake connection.

Which models and part numbers is this compatible with?

This Koubliztic kit is made to replace specific Bolens/Murray/MTD carburetor parts and fits numerous Briggs & Stratton engine variants listed by manufacturer reference. Cross-referenced part numbers and compatible codes increase the chance of a correct match for your mower.

• Direct replacement for part numbers: 799583, 593261, 595656, 591979, 591160, 590556, 799579.
• Compatible with multiple OEM codes such as 08P502-0034-F1 through 09P702-0128-F1 series.
• Designed for Bolens 21" mowers 11A-B0BL765 and 11A-020W765 with 125–140cc engines.
• Works with B&S 300E, 450E, 500E and 550EX engine series on specified models.

What comes in the kit and why are those parts useful?

Beyond the carburetor body, this kit supplies the small components that commonly fail or are replaced during carburetor service, letting you complete the repair in one session without extra trips to the parts store.

• 1 x 799583 carburetor — the core replacement unit for fuel metering.
• 1 x spark plug and 1 x primer bulb to improve starting reliability.
• 2 x air filters plus 1 x air filter cover to keep dirt out of the carburetor.
• Fuel filter, fuel shutoff valve, hoses, rings and throat clamps for secure, clean fuel delivery.

How durable is this replacement and what maintenance helps longevity?

The carburetor is manufactured from robust materials designed to endure routine mowing conditions. Regular maintenance—clean air filters, fresh fuel, and periodic inspection—helps protect internal passages and extend service life.

• Corrosion-resistant materials for longevity in outdoor environments.
• Replace air filters and fuel filter at manufacturer-recommended intervals.
• Use clean, stabilized fuel to prevent varnish and clogging.
• Store the mower with fuel shutoff closed to reduce carburetor fouling.

Who is this for: This Koubliztic carburetor kit is intended for homeowners, small-property landscapers, and DIY mechanics who own a Bolens 21" lawn mower with a 125–140cc engine or those with compatible Briggs & Stratton series engines listed in the compatibility section. It's ideal if you want a single, parts-complete replacement to fix poor starting, inconsistent idling, or fuel delivery issues without sourcing individual components.