Kawasaki FH721D-S01 Engine

With 1-1/8" X 3.94" Horizontal Shaft 25hp Kawasaki Engine

Comes with Duel Element Air Cleaner (flat on top) and Muffler

The Kawasaki FH721D-S01 is a 25-horsepower, 4-stroke OHV V-Twin engine built to deliver commercial-grade power and performance in a compact, lightweight design. Featuring a 1-1/8″ x 3.94″ horizontal shaft, dual-element air cleaner (flat-top design), and a factory-installed muffler, this model is engineered to perform under pressure — whether you’re repowering a John Deere, Scag, Exmark, Toro, or Bad Boy zero-turn mower, or driving another piece of heavy-duty outdoor equipment.

At Carroll Stream Motor Company, we proudly carry the FH721D-S01 as one of Kawasaki’s most trusted engines for both residential and commercial applications. Designed for easy installation and long-term durability, it combines power, reliability, and simplicity for operators who demand consistent performance season after season.

The FH721D-S01 packs 25 horsepower into a 675 cc V-Twin block, offering exceptional torque and smooth operation even under heavy load. Its 4-bolt mounting pattern and horizontal shaft configuration make it ideal for tight engine bays or compact machinery. At just 97 lbs dry weight, this model provides the perfect balance of lightweight handling and industrial-grade output.

Kawasaki’s engineering ensures quiet, efficient combustion and minimal vibration — a key advantage for professional landscapers and equipment owners who rely on consistent power without fatigue or downtime. This model features pressure lubrication with a full-flow oil filter to protect key internal components, ensuring reliable performance over thousands of hours of use. The pulse-driven fuel pump and mechanical governor keep engine performance steady across varying workloads, while the forced-air cooling system maintains optimal temperature in demanding conditions.

The standout feature of this unit — its dual-element Donaldson-style air cleaner — provides superior filtration, preventing dust and debris from entering the intake. This is especially beneficial for mowing, farming, or construction environments where dust and dirt are unavoidable.

Equipped with a 12-volt Bendix-type electric starter and a 15 AMP charging system with regulator, the FH721D-S01 starts instantly in any season. Operators can count on a quick start, consistent idle, and stable acceleration. The engine’s cast-iron cylinder liners and precision-balanced crankshaft further enhance smoothness and service life. Whether you’re a professional landscaper, property manager, or homeowner looking to repower your mower, this Kawasaki engine offers exceptional reliability and the torque you need for the toughest tasks.

We stock a full line of Kawasaki FH and FX series engines, plus replacement parts, tune-up kits, and accessories — so your equipment stays powerful and productive year-round. The Kawasaki FH721D-S01 offers the perfect blend of compact design, high torque, and legendary Kawasaki reliability. It’s built for professionals who need consistent performance, easy starting, and long-term dependability in demanding conditions.

Order your FH721D-S01 25HP engine today from Carroll Stream Motor Company and experience the difference that true commercial-grade power makes. For fitment assistance or additional specifications, call our team at 1-888-208-2088 or 248-628-4638.