When a critical part wears out in your Kawasaki FJ400D/BS04 small engine, getting back to full operation starts with genuine OEM components. Repair Clinic stocks a comprehensive inventory of Kawasaki FJ400D/BS04 parts sourced directly from the manufacturer, covering everything from the kawasaki FJ400D/BS04 carburetor and ignition coil to the FJ400D/BS04 oil filter and air filter. The FJ400D/BS04 is a four-stroke single-cylinder engine widely used in residential lawn mowers and outdoor power equipment, and whether you are working from the kawasaki FJ400D parts diagram to identify a failed component or already know which part you need from the FJ400D/BS04 parts list, this page has the genuine OEM replacements and repair resources to complete your repair with confidence.
About Kawasaki Small Engine FJ400D Parts
The Kawasaki FJ400D/BS04 is a compact overhead-valve engine built for dependable performance in residential equipment. Regular use in dusty outdoor conditions puts consistent demand on wear items like the carburetor, air filter, spark plug, and oil seals, and timely replacement with genuine OEM parts is the most effective way to maintain performance and prevent more costly internal damage. The complete Kawasaki small engine parts catalog covers the FJ400D/BS04 across all build variants, letting you filter by part category or symptom to find exactly what your engine needs.
Common Kawasaki FJ400D/BS04 Replacement Parts
Kawasaki FJ400D Carburetor
The carburetor mixes fuel and air in the correct ratio for combustion across all throttle positions. Over time, ethanol-blended fuel left in the carburetor between operating seasons breaks down into a varnish residue that clogs the main jet and float needle passage, causing hard starting, rough running at idle, or an engine that starts and then stalls. Cleaning often resolves light contamination, but a carburetor with corroded passages or a failed float needle is best replaced with a genuine OEM unit to restore consistent fuel delivery and reliable starting.
FJ400D/BS04 Air Filter
The air filter on the Kawasaki FJ400D/BS04 engine protects internal components from the dust, grass particles, and debris that circulate around outdoor equipment during operation. A saturated or collapsed filter element chokes the engine’s air supply, producing a rich running condition that fouls the spark plug, reduces power output, and increases fuel consumption. Replacing the filter at the beginning of each operating season, or more frequently in dusty conditions, is one of the highest-value maintenance steps available for this engine. For diagnosis of airflow-related running problems, the Kawasaki small engine troubleshooting center provides symptom-based guidance.
Spark Plug for the Kawasaki FJ400D/BS04
The spark plug ignites the compressed fuel-air mixture in the engine cylinder on every power stroke. A worn electrode, cracked porcelain insulator, or fouled plug produces a weak or absent spark that causes hard starting, misfires under load, or rough idle. The Kawasaki FJ400D/BS04 specifies a particular plug type, gap setting, and heat range, and using a non-OEM substitute that does not match these values can cause performance problems even when the plug appears serviceable. Inspecting and replacing the spark plug at the start of each season is a cost-effective preventive step.
Kawasaki FJ400D/BS04 Small Engine Oil Seal
Oil seals on the FJ400D/BS04 are fitted where the crankshaft exits the engine block, preventing engine oil from leaking externally or migrating into the air filter and carburetor. A degraded seal leads to visible oil loss, potential contamination of nearby components, and a risk of engine damage if oil levels drop without notice. OEM Kawasaki FJ400D/BS04 oil seals are manufactured from materials compatible with the engine’s lubricants and operating temperatures for a long-lasting, leak-free fit.
Kawasaki FJ400D Ignition Coil
The ignition coil converts low-voltage current into the high-voltage spark the plug needs to fire reliably. A failing coil on the Kawasaki FJ400D/BS04 often produces intermittent symptoms such as misfiring that worsens as the engine heats up, or an engine that starts when cold but dies after reaching operating temperature, because the coil’s internal windings break down under thermal stress. A genuine OEM replacement coil is pre-gapped to the flywheel air gap specification and restores strong, consistent spark across the engine’s full operating temperature range.
Find the Right Kawasaki FJ400D/BS04 Parts at Repair Clinic
- Certified Kawasaki OEM Components: Every FJ400D/BS04 part meets original factory specifications for accurate fit and lasting engine performance.
- Parts Diagram and Repair Videos: The kawasaki FJ400D/BS04 parts diagram and model-specific how-to videos guide your repair from diagnosis to completion.
- Priority Shipping on In-Stock Orders: Parts ship fast to minimize equipment downtime during the operating season.
- 365-Day Returns: Return any uninstalled part within a full year. Questions? The Repair Clinic contact page connects you with our team directly.
Frequently Asked Questions: Kawasaki FJ400D Parts
What are the most common replacement parts for the Kawasaki FJ400D/BS04?
The most frequently replaced parts on the Kawasaki FJ400D/BS04 are the carburetor, air filter, and spark plug. Keeping these components in good condition is essential for reliable starting, smooth operation under load, and fuel efficiency. The FJ400D/BS04 oil filter and oil seal are also common service items on higher-hour engines.
How do I know when the FJ400D/BS04 carburetor needs to be cleaned or replaced?
Symptoms of a carburetor problem on the Kawasaki FJ400D/BS04 include hard starting after storage, rough idle, stalling under load, or an engine that starts and runs for a short time before dying. Cleaning with carburetor cleaner often resolves light varnish buildup. If the carburetor has damaged internal passages, a stuck float needle, or a cracked bowl gasket, replacement with a genuine OEM unit is the more reliable repair.
How often should I replace the air filter on my Kawasaki FJ400D/BS04?
Under normal conditions, replacing the air filter at the start of each season or after every 25 hours of operation is a sound practice. Dusty operating environments warrant more frequent inspection and replacement. A clogged filter directly reduces engine power and starting reliability, making regular filter maintenance one of the most effective ways to extend engine life on the FJ400D/BS04.
Where can I find the Kawasaki FJ400D/BS04 parts diagram?
The Kawasaki FJ400D/BS04 parts diagram is available on this product page at Repair Clinic under the Diagrams tab. Components are organized by assembly section, including the carburetor group, cylinder head, and crankcase, making it straightforward to identify the correct part and confirm the right variant before ordering.
