To Next PageTo Next Page
Need help?Do you have a question about the Kawasaki FH721D and is the answer not in the manual?
Graphical representation of engine output and torque across different speeds.
Graphical representation of engine output and torque across different speeds.
The Kawasaki FH721D is a robust, air-cooled, 4-stroke, horizontal shaft, Overhead Valve (OHV) gasoline engine, designed for demanding applications. Its V-Twin cylinder layout ensures smooth operation and balanced power delivery, making it a reliable choice for a variety of heavy-duty equipment. This engine is engineered to provide consistent performance and durability, embodying Kawasaki's commitment to quality and innovation in power products.
The FH721D engine operates on a conventional 4-stroke cycle, converting the chemical energy of gasoline into mechanical energy to power external machinery. Its V-Twin configuration, with cylinders arranged at a 90-degree angle, contributes to reduced vibration and improved balance, which translates into a more comfortable user experience and extended engine life. The Overhead Valve (OHV) design allows for more efficient combustion and better fuel economy by optimizing valve placement for improved airflow into and out of the cylinders.
A key feature of this engine is its Full Transistor Ignition (FTI) system. The FTI system provides precise ignition timing, ensuring reliable starting and consistent spark delivery across all operating conditions. This electronic ignition system eliminates the need for mechanical breaker points, reducing maintenance requirements and improving overall engine reliability. The precise timing also contributes to more complete combustion, leading to lower emissions and better fuel efficiency.
The FH721D incorporates a Pressurized Lubrication System, a critical feature for engines operating under varying loads and angles. This system uses an oil pump to force oil through a spin-on oil filter and then to critical engine components, such as the crankshaft bearings, connecting rod bearings, and camshaft. Pressurized lubrication ensures that all moving parts receive a continuous supply of clean oil, even during heavy use or when the engine is tilted. This significantly reduces wear and tear, prolonging the engine's lifespan and maintaining its performance over time. The spin-on oil filter efficiently removes contaminants from the oil, further protecting internal components from abrasive particles.
The engine is equipped with a Dual Element Air Cleaner, designed to provide superior filtration in dusty or dirty environments. This two-stage filtration system effectively captures a wide range of particulate matter, preventing it from entering the combustion chamber and causing damage. The first element typically removes larger particles, while the second, finer element traps smaller contaminants. This robust air filtration system is essential for maintaining engine health and performance, especially in outdoor power equipment applications where exposure to dust and debris is common.
Power output is managed by a mechanical governor, which automatically adjusts the throttle to maintain a consistent engine speed under varying loads. This ensures that the connected equipment operates at its optimal speed, regardless of the demands placed upon it. The governor's responsiveness helps prevent engine bogging down or over-speeding, contributing to smoother operation and protecting both the engine and the driven machinery.
For starting, the FH721D utilizes a BENDIX type electric starter. This reliable starting mechanism allows for quick and effortless engine ignition, enhancing user convenience. The electric starter is powered by a 12V-13A charging coil with a regulator, which recharges the battery during engine operation, ensuring that the starter is always ready for use.
The FH721D engine is designed for ease of use and adaptability across various applications. Its horizontal shaft configuration makes it suitable for a wide range of equipment, including lawn and garden tractors, commercial mowers, generators, pressure washers, and other industrial machinery. The engine's compact design, despite its powerful output, allows for integration into diverse equipment frames without excessive bulk.
The twin barrel, float-type carburetor with a fixed main jet ensures consistent fuel delivery and optimal air-fuel mixture for efficient combustion. This type of carburetor is known for its reliability and ease of maintenance. A pulse-type fuel pump ensures a steady supply of fuel to the carburetor, even when the fuel tank is located below the engine, which is common in many equipment designs.
The engine's operational speeds are clearly defined, with a fast idle speed of 3600 rpm for maximum power output and a slow idle speed of 1550 rpm for reduced noise and fuel consumption when the engine is not under load. The direction of rotation is counter-clockwise when facing the PTO (Power Take-Off) shaft, a standard configuration that simplifies integration with many types of driven equipment.
For user convenience and safety, the engine is designed to meet RFI (Radio Frequency Interference) requirements as per Canadian and U.S.A. standards, minimizing interference with electronic devices. The low tone type muffler is engineered to reduce noise levels during operation, contributing to a more comfortable working environment and compliance with noise regulations.
The engine's oil capacity, including the filter, is specified to ensure adequate lubrication for extended periods between oil changes, reducing the frequency of maintenance checks. The presence of a spin-on oil filter simplifies the oil change process, making it a more user-friendly task.
Maintenance of the FH721D is designed to be straightforward, ensuring longevity and consistent performance. The pressurized lubrication system with a spin-on oil filter is a significant maintenance advantage. The filter is easily accessible for replacement, and the system ensures that clean oil circulates throughout the engine, reducing wear and extending the life of critical components. Regular oil and filter changes are crucial for maintaining the integrity of this system.
The dual element air cleaner is another feature that simplifies maintenance. Its design allows for easy inspection and cleaning or replacement of the filter elements. Regular servicing of the air cleaner is vital, especially when operating in dusty conditions, to prevent contaminants from entering the engine and causing damage.
The Full Transistor Ignition system, being electronic, requires minimal maintenance compared to traditional ignition systems with breaker points. There are no points to clean or adjust, which reduces the complexity and frequency of ignition system servicing. The recommended spark plug, NGK BPR4ES, is a standard and readily available component, making replacements simple.
The mechanical governor is a robust system that typically requires little maintenance beyond ensuring its linkages are free and unobstructed. Its design contributes to reliable engine speed control without frequent adjustments.
The engine's overall construction, including its durable materials and robust design, contributes to its low maintenance profile. Kawasaki engines are known for their reliability, and the FH721D is built to withstand demanding use. Adhering to the recommended maintenance schedule, including regular checks of fluid levels, filter replacements, and spark plug inspections, will ensure the engine continues to perform optimally for many years. The availability of detailed dimensional specifications also aids in any necessary repairs or component replacements, ensuring that the correct parts are used and fitted properly.
General| Fuel System | Carburetor |
|---|---|
| Displacement | 726 cc |
| Bore x Stroke | 78 x 76 mm |
| Ignition System | Magneto |
| Oil Capacity | 2.1 liters |
| Starting System | Electric starter |
| Lubrication System | Forced lubrication |
