KAWASAKI® 25.5 HP STD (FX801V-MS00S)

KAWASAKI® 25.5 HP STD Engine, FX801V-MS00S

The Kawasaki® FX801V-MS00S is a commercial-grade 25.5 HP vertical shaft engine built for demanding mowing and turf applications. Part of Kawasaki’s FX Series, this 852 cc V-twin engine delivers strong, smooth power with the durability features needed for long hours, heavy grass, high temperatures, and regular professional use.

At the heart of the FX801V is a 4-stroke, air-cooled, 90-degree V-twin OHV design with 2 cylinders, a 3.33 in. x 2.99 in. bore and stroke, and an 8.2:1 compression ratio. Kawasaki rates this engine at 25.5 HP at 3,600 RPM, with 45.8 ft-lbs of torque at 2,200 RPM, giving it the low-end pulling power needed for larger mower decks, slopes, thick turf, and commercial cutting conditions.

The FX801V-MS00S is designed for reliability and serviceability. It features cast-iron cylinder liners, a pressurized lubrication system, high-efficiency oil cooler, electronic spark ignition, automatic compression release, and a heavy-duty shift-type starter. These features help support easier starting, consistent oil delivery, improved heat control, and longer engine life in tough operating conditions.

A multi-stage canister air filter helps protect the engine in dusty mowing environments, while the rotating metal grass chopper screen and metal engine cover with integrated clean-out ports help manage debris around the cooling system. The twin-barrel carburetor with fuel shut-off solenoid supports dependable fuel delivery and helps reduce run-on after shutdown.

With a dry weight of approximately 124 lb and an oil capacity of 2.4 U.S. qt with filter, this engine is well suited for heavy-duty zero-turn mowers, commercial riding mowers, and replacement engine applications where a powerful vertical shaft engine is required. Dimensions are listed by Kawasaki at approximately 19.21 in. x 18.30 in. x 24.64 in.

Common use cases

The Kawasaki FX801V-MS00S is a strong choice for commercial zero-turn mowers, large residential zero-turn mowers, professional landscaping equipment, municipal turf maintenance machines, estate property mowers, and other vertical shaft applications requiring dependable high-output gasoline power. It is especially useful for operators cutting large areas, mowing in thick or wet grass, running wider mower decks, or replacing an existing compatible Kawasaki FX Series engine.

Key specifications

Note: Always confirm crankshaft size, mounting pattern, muffler requirements, wiring, controls, and application compatibility before ordering a replacement engine. The FX801V family may be available in multiple configurations, and the correct spec number matters.

Order online across Canada or visit us in store in Calgary, Alberta.