Carbhub 591731 Carburetor Replacement – 31H777 & 2015+ Engine Fits | Toro & Cub Cadet

Upgrade your outdoor power equipment with Carbhub

When it’s time to replace a carburetor, you want a part that fits your machine and performs consistently. The Carbhub 591731 replacement is designed for contemporary engines and a broad range of popular models. It supports reliable fuel delivery and steady throttle response across everyday lawn care tasks. This carburetor is compatible with 31H777 and related vertical-shaft engines, covering 13.5 HP to 17.5 HP variations, and is a fit for common Toro lawn tractors and Cub Cadet riding mowers.

Engineered with a focus on compatibility and practical installation, the 591731 integrates with engines manufactured in 2015 or later. It is not recommended for machines built before 2015, ensuring you’re choosing a modern variant that aligns with current components and fuel systems.

Compatibility at a glance

• Supports 31H777, 28AH76, 28AH77, 28BH76, 28BH77, 28CH77, and 31A507-series engines in the 13.5–17.5 HP range.
• Suitable for Toro models such as 71286 (2005–2007), 71427, 71428, 71429, 74301, 74325, 74327, 74330, and Cub Cadet LT1018 / RZT17 / RZT42 lines.
• Designed for engines manufactured in 2015 or later; not compatible with pre-2015 machines.

Kit contents and quick installation

• 1x Carburetor, 1x Air Filter, 1x Spark Plug, 1x Fuel Filter, 1x Gasket
• 8x Clamps, 2x Fuel Lines, 1x Fuel Shut Off Valve

What to expect in use

While no replacement can guarantee immediate performance changes, this kit provides a complete set of components that can facilitate a straightforward swap and consistent fuel flow. The included gasket and clamps support a secure seal and reliable connections during operation. If your current setup uses old parts or improper seals, this kit offers a practical path to restoring alignment between fuel delivery and air intake, which is a sensible step in routine maintenance.

Durability and design

The 591731 carburetor features a robust metallic finish and precisely machined passages to help maintain reliable metering across varying engine loads. A snug gasket interface and vibration-resistant seals contribute to steady operation in outdoor conditions, while the compact form helps with accessible replacement in crowded engine bays.

Installation tips

Before installing, verify part numbers and ensure mounting surfaces are clean. Safely drain old fuel to reduce debris. Replace the air filter and spark plug if they show wear. After installation, check seals and clamps for a secure fit and test throttle movement for smooth operation.