Kawasaki FH721V-S24 25HP Vertical Shaft Engine
The Kawasaki FH721V-S24 is a 25 HP, 675cc commercial V-Twin gasoline engine with a 1-1/8-inch (28.5 mm) diameter x 3-15/16-inch (100 mm) keyed vertical PTO shaft.
This FH721V-S24 configuration features electric start, a 15-amp charging system and a heavy-duty canister/snorkel air cleaner. It is a replacement-engine configuration commonly used on commercial zero-turn mowers and other equipment originally equipped with compatible Kawasaki FH721V S24 specifications.
Limited Remaining FH721V-S24 Inventory: Carroll Stream is offering remaining FH721V-S24 inventory at current sale pricing while supplies last.
If your equipment specifically calls for an FH721V-S24 or related S24 specification, verify fitment before ordering.
FH721V-S24 Key Specifications
| Kawasaki FH721V-S24 Engine Specifications | |
|---|---|
| Manufacturer | Kawasaki |
| Engine Model | FH721V |
| Specification / Sales Configuration | FH721V-S24 |
| Common Replacement Listing | FH721V-S24-S |
| Engine Type | 4-Stroke OHV 90° V-Twin |
| Shaft Orientation | Vertical |
| Displacement | 675cc / 41.2 cu. in. |
| Maximum Horsepower | 25 HP @ 3,600 RPM |
| Maximum Torque | 41.3 ft-lb @ 2,400 RPM |
| Bore x Stroke | 2.96 x 2.99 in. / 75.2 x 76 mm |
| PTO Shaft Diameter | 1-1/8 in. / approximately 28.5 mm |
| PTO Shaft Length | 3-15/16 in. / approximately 100 mm |
| Shaft Type | Keyed Straight Shaft |
| Starting System | Electric Bendix Start |
| Charging System | 15 Amp |
| Air Cleaner | Heavy-Duty Canister / Snorkel Air Cleaner |
| Cooling | Forced Air Cooling |
| Lubrication | Full-Pressure Lubrication With Oil Filter |
| Oil Capacity With Filter Change | Approximately 1.8 L / 1.9 US qt. |
| Fuel | Clean, Fresh Unleaded Gasoline – Minimum 87 Octane |
| Fuel Tank | Not Included |
| Muffler | Not Included |
| Manufacturer Warranty | 3-Year Engine Manufacturer Warranty |
What Is the Kawasaki FH721V-S24?
FH721V-S24 identifies a specific configuration of Kawasaki's FH721V vertical-shaft V-Twin engine. The S24 specification matters because Kawasaki produced FH721V engines with different PTO shafts, air cleaners, electrical systems, muffler configurations and equipment-specific components.
A generic FH721V engine is therefore not automatically interchangeable with an FH721V-S24. Replacement should be based on the complete engine specification and physical installation requirements.
FH721V-S24 and FH721V-S24-S
Replacement-engine catalogs may list this configuration as FH721V-S24-S. Customers searching for either FH721V-S24 or FH721V-S24-S should verify the identification from their original engine and equipment before ordering.
Kawasaki also produced multiple production revisions within the S24 specification family. Replacement-engine catalogs associate the current S24 replacement configuration with several earlier suffix versions.
FH721V S24 Replacement Specifications
Published replacement-engine data identifies the S24 configuration as a replacement path for the following FH721V specification numbers:
Important: This replacement information applies to the specific S24-family configurations above. It does not mean FH721V-S24 is a universal drop-in replacement for every FH721V, FH680V, FH641V or FH601V.
FH721V-S24 Shaft Size
One of the most important FH721V-S24 fitment characteristics is its 1-1/8-inch diameter x 3-15/16-inch long vertical keyed crankshaft.
In metric dimensions, the shaft is approximately 28.5 mm in diameter x 100 mm long. Shaft diameter and length should be checked against the original engine before purchasing a replacement.
Heavy-Duty Air Cleaner
The FH721V-S24 replacement configuration uses a heavy-duty canister-style air cleaner, sometimes described in replacement-engine catalogs as a snorkel air cleaner.
This is another important difference between FH721V specifications. An FH721V with a different air-cleaner arrangement should not be assumed to have identical equipment clearance or intake routing.
Does FH721V-S24 Include a Muffler?
No. Current replacement-engine specifications for FH721V-S24-S identify the engine as being supplied without a muffler.
Verify whether the existing equipment muffler and exhaust arrangement can be reused or whether additional exhaust components are needed before installation.
FH721V-S24 Charging System
The FH721V-S24 replacement configuration is listed with a 15-amp charging system and electric Bendix starter.
Electrical connections and equipment wiring should still be compared with the original engine before installation.
Kawasaki FH721V Engine Specifications
Kawasaki rates the FH721V engine family at 25 HP at 3,600 RPM with 41.3 ft-lb of maximum torque at 2,400 RPM. The engine uses a 675cc, 90-degree OHV V-Twin configuration with a 2.96-inch bore and 2.99-inch stroke.
The FH721V also uses forced-air cooling, full-pressure lubrication and a replaceable oil filter. Kawasaki documentation specifies approximately 1.9 US quarts of oil when the oil filter is changed.
What Fuel Does the FH721V-S24 Use?
Kawasaki specifies clean, fresh, unleaded regular gasoline with a minimum 87-octane antiknock index for FH-series engines.
The older 86-octane specification sometimes shown in reseller descriptions should not be used for this page.
Common FH721V-S24 Applications
FH721V-S24 configurations are commonly used as replacement engines for compatible commercial mowing equipment, including zero-turn mower applications.
Replacement-engine catalogs list FH721V-S24-S for applications associated with manufacturers such as Ferris, Lesco and select John Deere equipment. Equipment model alone is not sufficient to guarantee fitment because manufacturers may use different engine specifications during a model's production run.
Do not buy solely by mower brand, horsepower or shaft diameter. Verify the original Kawasaki engine model/specification, PTO shaft dimensions, wiring, exhaust arrangement and equipment clearance.
Before Ordering an FH721V-S24 Replacement Engine
- Confirm the original engine is a Kawasaki FH721V S24-family specification.
- Record the complete model/specification from the engine identification label.
- Verify the 1-1/8" x 3-15/16" vertical keyed PTO shaft.
- Verify the heavy-duty canister/snorkel air-cleaner configuration.
- Confirm the equipment's electrical connections and charging requirements.
- Verify the existing muffler/exhaust arrangement because the replacement engine is supplied without a muffler.
- Check physical engine and air-cleaner clearance before installation.
Need help confirming the correct Kawasaki FH721V replacement? Call Carroll Stream Motor Company at 1-888-208-2088 with the original engine specification and equipment model.
Kawasaki FH721V-S24 FAQs
What is the Kawasaki FH721V-S24?
The Kawasaki FH721V-S24 is a 25 HP, 675cc vertical-shaft OHV V-Twin engine configuration with a 1-1/8" x 3-15/16" keyed PTO shaft and heavy-duty air cleaner.
How much horsepower does the FH721V-S24 have?
Kawasaki rates the FH721V engine at 25 HP at 3,600 RPM.
What size shaft does the Kawasaki FH721V-S24 have?
The FH721V-S24 uses a 1-1/8-inch diameter x 3-15/16-inch long vertical keyed shaft, approximately 28.5 x 100 mm.
What is the difference between FH721V-S24 and FH721V-S24-S?
FH721V-S24-S is a sales/listing format commonly used by replacement-engine distributors for the S24 engine configuration. Always compare the original engine identification and exact replacement specifications before ordering.
What engines does FH721V-S24-S replace?
Published replacement-engine data lists the S24 replacement configuration for FH721V-AS24S, FH721V-BS24S, FH721V-CS24S, FH721V-DS24S, FH721V-ES24S and FH721V-FS24S applications.
Does FH721V-S24 include a muffler?
No. Current FH721V-S24-S replacement-engine specifications identify the engine as being supplied without a muffler.
What charging system does FH721V-S24 use?
The FH721V-S24 replacement configuration uses a 15-amp charging system.
Does FH721V-S24 have a heavy-duty air cleaner?
Yes. The S24 replacement configuration uses a heavy-duty canister or snorkel-style air cleaner.
What is the displacement of FH721V-S24?
The Kawasaki FH721V has a displacement of 675cc / 41.2 cubic inches.
How much torque does a Kawasaki FH721V make?
Kawasaki's FH721V specification lists maximum torque of approximately 41.3 ft-lb at 2,400 RPM.
What fuel does the FH721V-S24 use?
Kawasaki specifies clean, fresh unleaded regular gasoline rated at a minimum of 87 octane.
Is FH721V-S24 a direct replacement for FH680V?
Not universally. Although some equipment may be repowered with related Kawasaki FH engines, shaft dimensions, wiring, air cleaner, exhaust and equipment-specific configuration must all be verified.
How do I confirm FH721V-S24 fits my mower?
Compare the complete original Kawasaki engine specification, PTO shaft dimensions, electrical connections, exhaust arrangement and equipment clearance. Contact Carroll Stream with the original engine and equipment information if help is needed.
1 Review
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Kawasaki lawnmower engine
We have a 21 year old commercial lawnmower with a Kawasaki engine that had quit. Instead of buying a $11,000.00 new mower we ordered another engine. Everything fit and there was no adjustments needed. Carollstream cross referenced the engine we needed and got the motor to us in 3 days. One half day to install and we were cutting the yard again as good as new!
