The 2021 Kawasaki Ninja 400 is a popular, lightweight sportbike introduced in 2018, succeeding the Ninja 300. It features a full-faired body style and is available in standard and KRT Edition trims, priced new around $4,999-$5,599. Its blend of accessible power, agile handling, aggressive styling, and exceptional value makes it a standout choice for both beginner riders and those seeking a fun, capable machine. Its "big bike" look in a manageable package contributes to its wide appeal.
The Good
The 2021 Ninja 400 excels with its spirited performance, offering a thrilling yet manageable ride for emotional buyers. Practically, its renowned Kawasaki reliability, impressive fuel efficiency, and comfortable ergonomics make it a smart choice. Its aggressive design and strong value, coupled with low ownership costs, appeal to a wide range of riders seeking both excitement and sensible ownership.
The Bad
While highly capable, the 2021 Ninja 400's primary weaknesses include its basic, non-adjustable suspension and adequate but not exceptional single front disc brake setup. Taller riders might find wind protection limited, and the passenger seat offers minimal comfort for long rides. Minor vibrations can also be noticed at higher engine speeds.
2021 Kawasaki Ninja 400: Quick Overview
- Engine: The 2021 Kawasaki Ninja 400 is powered by a 399cc, liquid-cooled, 4-stroke, DOHC, 8-valve parallel-twin engine, known for its smooth power delivery and broad torque curve, making it accessible for new riders yet engaging for experienced ones.
- Horsepower: This engine typically produces around 44.8 horsepower at the crank, translating to approximately 39-40 horsepower at the rear wheel, offering ample power for highway cruising and spirited canyon carving.
- Fuel Economy: Riders can expect excellent fuel efficiency, with an EPA estimated average of about 56 MPG. Real-world usage often sees figures ranging from 50 to 65 MPG, depending on riding style, making it very economical for daily commuting or touring.
- 0-60 MPH: The Ninja 400 can accelerate from 0 to 60 MPH in an impressive estimated time of approximately 4.5 to 5.0 seconds, putting it ahead of many cars and providing a thrilling rush.
- Towing Capacity: As a sport motorcycle, the 2021 Kawasaki Ninja 400 has no towing capacity; it is not designed or rated for towing purposes.
- Trim-Level Features:
- Standard Model: Features include a lightweight trellis frame contributing to its agile handling, an Assist & Slipper clutch system that provides a light clutch pull and prevents rear-wheel hop during aggressive downshifts, and powerful single front (310mm) and rear (220mm) petal disc brakes, often equipped with optional ABS for enhanced safety. It boasts modern LED headlamps and tail lights for superior visibility. The instrumentation includes an analog tachometer complemented by a multi-function LCD screen displaying gear position, fuel level, odometer, dual trip meters, and a clock. Its relatively relaxed, sport-oriented ergonomics offer a good balance of comfort and control.
- KRT Edition: This trim includes all the features of the standard model but distinguishes itself with an exclusive Kawasaki Racing Team (KRT) livery, featuring vibrant race-inspired graphics and colors that pay homage to Kawasaki's factory racing efforts. Mechanically, it is identical to the standard Ninja 400.
2021 Kawasaki Ninja 400 Specifications
Vehicle Information
| Year | 2021 |
| Make | Kawasaki |
| Model | Ninja 400 |
| Trim | - |
| Style | - |
| Type | Motorcycle |
| Category | Motorcycle |
Manufacturing Details
| Made In | Japan |
| Manufacturing City | AMPHUR PLUAK DAENG |
Dimensions
| Doors | - |
| Curb Weight | - |
| Gross Vehicle Weight Rating | - |
| Overall Height | - |
| Overall Length | - |
| Overall Width | - |
| Wheelbase Length | - |
| Standard Seating | - |
Engine & Performance
| Engine | 399CC |
| Engine Size | 399L |
| Engine Cylinders | 2 |
| Transmission | - |
| Transmission Type | - |
| Transmission Speeds | - |
| Drivetrain | - |
Additional Features
| Anti-Brake System | - |
| Steering Type | - |
Pricing
| Manufacturer Suggested Retail Price (MSRP) | - |
| Invoice Price | - |
| Delivery Charges | - |
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What Problems Does the 2021 Kawasaki Ninja 400 Have?
The 2021 Kawasaki Ninja 400 generally boasts a strong reputation for reliability, carrying Kawasaki's dependable engineering. However, like any vehicle, some frequently reported observations and minor concerns have emerged. One common point for enthusiasts is the stock suspension system, which, while adequate for general riding, is non-adjustable and can feel overly soft or bouncy for more aggressive riders or those with higher body weights, prompting some owners to seek aftermarket upgrades for improved damping and adjustability. The braking system, featuring a single front disc, is competent but some riders desire more initial bite and stronger stopping power, occasionally wishing for a dual-disc setup.
Minor vibrations are sometimes noted through the handlebars and footpegs, particularly at higher RPMs, though these are typically within acceptable limits for a parallel-twin engine in this class. Related to this, some owners report that the rearview mirrors can experience slight blurring due to vibrations at certain engine speeds. Wind protection can be a minor concern for taller riders, who might experience more wind buffeting compared to larger sportbikes.
In terms of recalls specific to the 2021 model year, there haven't been any widespread, highly impactful safety recalls directly affecting the Ninja 400. Earlier model years (2018-2020) of the Ninja 400 did experience a recall concerning the ECU programming, which could potentially lead to engine stalling at idle speeds. However, by the 2021 model year, this issue was largely resolved through updated ECU software during manufacturing or via dealer service if any earlier models still required it.
Long-term reliability for the Ninja 400 is generally considered excellent. The 399cc parallel-twin engine is a robust and well-engineered unit, known for its durability when subjected to regular maintenance. Issues such as significant oil leaks or major engine component failures are extremely rare. The primary factors affecting its long-term health are consistent oil changes, chain maintenance, and adherence to the manufacturer's service schedule. Overall, the Ninja 400 is regarded as a dependable motorcycle with few critical long-term concerns, making it a reliable choice for extended ownership.
Minor vibrations are sometimes noted through the handlebars and footpegs, particularly at higher RPMs, though these are typically within acceptable limits for a parallel-twin engine in this class. Related to this, some owners report that the rearview mirrors can experience slight blurring due to vibrations at certain engine speeds. Wind protection can be a minor concern for taller riders, who might experience more wind buffeting compared to larger sportbikes.
In terms of recalls specific to the 2021 model year, there haven't been any widespread, highly impactful safety recalls directly affecting the Ninja 400. Earlier model years (2018-2020) of the Ninja 400 did experience a recall concerning the ECU programming, which could potentially lead to engine stalling at idle speeds. However, by the 2021 model year, this issue was largely resolved through updated ECU software during manufacturing or via dealer service if any earlier models still required it.
Long-term reliability for the Ninja 400 is generally considered excellent. The 399cc parallel-twin engine is a robust and well-engineered unit, known for its durability when subjected to regular maintenance. Issues such as significant oil leaks or major engine component failures are extremely rare. The primary factors affecting its long-term health are consistent oil changes, chain maintenance, and adherence to the manufacturer's service schedule. Overall, the Ninja 400 is regarded as a dependable motorcycle with few critical long-term concerns, making it a reliable choice for extended ownership.
How long will the 2021 Kawasaki Ninja 400 last?
The 2021 Kawasaki Ninja 400, when maintained diligently, is renowned for its excellent long-term durability. Owners frequently report achieving upwards of 50,000 miles without major mechanical issues, and it's not uncommon for these bikes to serve reliably for 5 to 10 years or more. The core 399cc parallel-twin engine is a robust unit, built to endure significant mileage with proper oil changes and valve adjustments at recommended intervals.
Over time, the primary areas requiring attention are typical wear items such as brake pads, tires, chains, and sprockets. Suspension components, including fork seals and fluid, will eventually need refreshing to maintain optimal performance. Cosmetically, fairings can show signs of wear, fading, or minor scratches. While the electrical system is generally reliable, like any motorcycle, battery longevity is dependent on usage and charging habits. Overall, the Ninja 400 is a very durable machine, designed for sustained use, with no inherent long-term weaknesses that aren't common to most motorcycles.
Over time, the primary areas requiring attention are typical wear items such as brake pads, tires, chains, and sprockets. Suspension components, including fork seals and fluid, will eventually need refreshing to maintain optimal performance. Cosmetically, fairings can show signs of wear, fading, or minor scratches. While the electrical system is generally reliable, like any motorcycle, battery longevity is dependent on usage and charging habits. Overall, the Ninja 400 is a very durable machine, designed for sustained use, with no inherent long-term weaknesses that aren't common to most motorcycles.
What Technology & Safety Features are Included?
The 2021 Kawasaki Ninja 400 focuses on functional, rider-centric technology rather than extensive infotainment. Its primary built-in tech features include a clear and informative instrument cluster, which combines an analog tachometer for immediate engine speed feedback with a multi-function LCD screen. This LCD display provides essential data such as digital speedometer, odometer, dual trip meters, a precise fuel gauge, a clock, and a very useful gear position indicator, along with instant and average fuel economy readouts and remaining range.
A significant performance and safety feature is the Assist & Slipper Clutch. This technology not only provides a remarkably light clutch lever pull, reducing rider fatigue, but also acts as a slipper clutch, preventing rear-wheel lock-up or hop during aggressive downshifts, thereby enhancing stability and control, particularly for newer riders.
For illumination, the Ninja 400 comes standard with modern and bright LED headlamps and tail lights, offering superior visibility for the rider and making the motorcycle more conspicuous to other road users.
Regarding driver-assistance and safety, the most prominent feature is the availability of Anti-lock Brake System (ABS). While not always standard on every variant or in every market, ABS is a highly recommended and often chosen optional feature, significantly enhancing braking safety by preventing wheel lock-up during hard braking or on slippery surfaces. The bike's lightweight trellis frame contributes to its agile handling, allowing riders to perform evasive maneuvers effectively.
Motorcycles, including the Ninja 400, do not undergo formal crash-test ratings by organizations like NHTSA or IIHS in the same way cars do. Safety on a motorcycle is predominantly a function of rider skill, protective gear, and the inherent dynamics of the machine. There are no built-in entertainment systems or advanced driver-assistance features like adaptive cruise control or lane-keeping assist, as the Ninja 400 is designed as a pure, engaging riding experience.
A significant performance and safety feature is the Assist & Slipper Clutch. This technology not only provides a remarkably light clutch lever pull, reducing rider fatigue, but also acts as a slipper clutch, preventing rear-wheel lock-up or hop during aggressive downshifts, thereby enhancing stability and control, particularly for newer riders.
For illumination, the Ninja 400 comes standard with modern and bright LED headlamps and tail lights, offering superior visibility for the rider and making the motorcycle more conspicuous to other road users.
Regarding driver-assistance and safety, the most prominent feature is the availability of Anti-lock Brake System (ABS). While not always standard on every variant or in every market, ABS is a highly recommended and often chosen optional feature, significantly enhancing braking safety by preventing wheel lock-up during hard braking or on slippery surfaces. The bike's lightweight trellis frame contributes to its agile handling, allowing riders to perform evasive maneuvers effectively.
Motorcycles, including the Ninja 400, do not undergo formal crash-test ratings by organizations like NHTSA or IIHS in the same way cars do. Safety on a motorcycle is predominantly a function of rider skill, protective gear, and the inherent dynamics of the machine. There are no built-in entertainment systems or advanced driver-assistance features like adaptive cruise control or lane-keeping assist, as the Ninja 400 is designed as a pure, engaging riding experience.
What Colors Options are Available?
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In the meantime, feel free to explore the other sections for more content.
In the meantime, feel free to explore the other sections for more content.
2021 Kawasaki Ninja 400 Prices and Market Value
When new, the 2021 Kawasaki Ninja 400 typically retailed for an MSRP starting around $4,999 for the standard model without ABS, climbing to approximately $5,299 with ABS, and the KRT Edition usually priced between $5,399 and $5,599. As of late 2023/early 2024, current used market prices for a well-maintained 2021 Ninja 400 generally range from $4,000 to $5,000, and sometimes slightly more for exceptional examples or KRT editions with desirable aftermarket parts.
The Ninja 400 demonstrates excellent depreciation characteristics, holding its value remarkably well for a motorcycle. This strong resale value is largely attributed to its enduring popularity, robust reliability, and its appeal to a broad market segment, including new riders. Factors significantly affecting its resale value include the overall physical condition (minimal fairing damage or scratches), mileage (lower mileage bikes fetching higher prices), the presence of ABS, and whether it's the visually distinct KRT Edition. Regular maintenance records and tasteful, reversible modifications can also positively influence its market price.
The Ninja 400 demonstrates excellent depreciation characteristics, holding its value remarkably well for a motorcycle. This strong resale value is largely attributed to its enduring popularity, robust reliability, and its appeal to a broad market segment, including new riders. Factors significantly affecting its resale value include the overall physical condition (minimal fairing damage or scratches), mileage (lower mileage bikes fetching higher prices), the presence of ABS, and whether it's the visually distinct KRT Edition. Regular maintenance records and tasteful, reversible modifications can also positively influence its market price.
2021 Kawasaki Ninja 400 Cost of Ownership
The 2021 Kawasaki Ninja 400 is widely regarded as an exceptionally economical vehicle to own in the long term. Insurance costs are generally quite affordable, especially for a sportbike, although premiums for new or very young riders might be higher. Its outstanding fuel efficiency, often yielding 50-65 MPG, results in very low fuel expenses. Maintenance is straightforward and budget-friendly, with common parts readily available and service intervals that are reasonable for its class. The robust engine design means major repair costs are rare, typically limited to wear-and-tear items like tires, brakes, and chain. Overall, the Ninja 400 presents a compelling package for riders seeking minimal long-term ownership expenditure.
2021 Kawasaki Ninja 400 Fuel Efficiency
Fuel Type
Gasoline
Fuel Capacity
-
City Mileage
-
Highway Mileage
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2021 Kawasaki Ninja 400 Warranty
Basic
Original warranty
0 months / No data
Estimated remaining
Expired
Powertrain
Original warranty
0 months / No data
Estimated remaining
Expired
Rust
Original warranty
0 months / No data
Estimated remaining
Expired
2021 Kawasaki Ninja 400 Insurance
Insurance for a 2021 Kawasaki Ninja 400 is moderately priced, reflecting its status as a Motorcycle with strong safety ratings and
reasonable repair costs.
reasonable repair costs.
How Does the 2021 Kawasaki Ninja 400 Compare to Other Motorcycle?
The 2021 Kawasaki Ninja 400 holds a strong position against its key rivals, often emerging as the class leader due to its balanced attributes.
Vs. Yamaha YZF-R3: The R3 is the Ninja 400's most direct competitor. In terms of performance, the Ninja 400 generally boasts a slight edge with its larger 399cc engine producing more torque and slightly higher horsepower (around 44.8 HP vs. R3's ~42 HP for the 321cc), especially in the mid-range, making it feel more potent and less rev-dependent. Both offer nimble handling and similar features like optional ABS. Reliability is excellent for both, being Japanese manufacturers. Price is very competitive, with the R3 often being marginally less or comparable. For an all-around performance advantage, the Ninja 400 usually wins.
Vs. KTM RC 390: The RC 390 is a more aggressive, track-focused alternative. Its single-cylinder engine delivers similar peak horsepower to the Ninja 400 but often with a more raw, vibey character. The RC 390 typically features higher-spec suspension (WP components) and brakes (ByBre), making it sharper for track days. However, its reliability, while improved, sometimes lags slightly behind the Japanese twins in perceived long-term robustness or minor issues, and maintenance can be a bit more frequent. Its price is usually higher. If pure sport riding and premium components are the priority, the RC 390 is a strong contender, but for daily usability and overall reliability, the Ninja 400 is often preferred.
Vs. Honda CBR300R & Suzuki GSX250R: These are generally a step below in performance, offering significantly less power (CBR300R around 30 HP, GSX250R around 25 HP) due to smaller, single-cylinder (Honda) or twin-cylinder (Suzuki) engines. Their features are more basic, and while both boast strong reliability, they simply don't offer the same level of excitement or highway capability as the Ninja 400. Their price is typically lower, appealing to absolute budget-conscious buyers or those seeking a very relaxed ride.
Recommendation: The 2021 Kawasaki Ninja 400 is arguably the best all-rounder in its class, offering an unparalleled blend of performance, reliability, modern features, and exceptional value. It's highly recommended for most riders. For those prioritizing a slightly smoother, higher-revving engine and equally strong reliability, the Yamaha R3 is a very similar, excellent alternative. If a more aggressive, track-oriented machine with premium components is desired and a slightly higher price/maintenance is acceptable, the KTM RC 390 is a consideration.
Vs. Yamaha YZF-R3: The R3 is the Ninja 400's most direct competitor. In terms of performance, the Ninja 400 generally boasts a slight edge with its larger 399cc engine producing more torque and slightly higher horsepower (around 44.8 HP vs. R3's ~42 HP for the 321cc), especially in the mid-range, making it feel more potent and less rev-dependent. Both offer nimble handling and similar features like optional ABS. Reliability is excellent for both, being Japanese manufacturers. Price is very competitive, with the R3 often being marginally less or comparable. For an all-around performance advantage, the Ninja 400 usually wins.
Vs. KTM RC 390: The RC 390 is a more aggressive, track-focused alternative. Its single-cylinder engine delivers similar peak horsepower to the Ninja 400 but often with a more raw, vibey character. The RC 390 typically features higher-spec suspension (WP components) and brakes (ByBre), making it sharper for track days. However, its reliability, while improved, sometimes lags slightly behind the Japanese twins in perceived long-term robustness or minor issues, and maintenance can be a bit more frequent. Its price is usually higher. If pure sport riding and premium components are the priority, the RC 390 is a strong contender, but for daily usability and overall reliability, the Ninja 400 is often preferred.
Vs. Honda CBR300R & Suzuki GSX250R: These are generally a step below in performance, offering significantly less power (CBR300R around 30 HP, GSX250R around 25 HP) due to smaller, single-cylinder (Honda) or twin-cylinder (Suzuki) engines. Their features are more basic, and while both boast strong reliability, they simply don't offer the same level of excitement or highway capability as the Ninja 400. Their price is typically lower, appealing to absolute budget-conscious buyers or those seeking a very relaxed ride.
Recommendation: The 2021 Kawasaki Ninja 400 is arguably the best all-rounder in its class, offering an unparalleled blend of performance, reliability, modern features, and exceptional value. It's highly recommended for most riders. For those prioritizing a slightly smoother, higher-revving engine and equally strong reliability, the Yamaha R3 is a very similar, excellent alternative. If a more aggressive, track-oriented machine with premium components is desired and a slightly higher price/maintenance is acceptable, the KTM RC 390 is a consideration.
Final Verdict: Is the 2021 Kawasaki Ninja 400 a Good Motorcycle?
The 2021 Kawasaki Ninja 400 is an outstanding motorcycle and absolutely worth buying. It is ideally suited for a wide range of riders, making it a true "goldilocks" bike. It's perfect for new riders seeking an approachable, confidence-inspiring sportbike with enough power to grow into, yet manageable handling. Experienced riders will appreciate its lightweight agility, surprisingly engaging performance, and economical running costs for a spirited daily commute or a fun track-day machine. Commuters will benefit from its excellent fuel economy and nimble urban maneuverability.
Whether bought new or used, the Ninja 400 represents fantastic value. Buying new offers the full warranty and the latest options, while a used model, thanks to its low depreciation and robust reliability, provides even greater savings. When buying used, prioritize models with ABS for enhanced safety. The KRT Edition offers a visually striking aesthetic, but mechanically, it's identical to the standard trim, so choose based on your visual preference and budget. Overall, the Ninja 400 delivers a balanced, thrilling, and sensible ownership experience for almost anyone.
Whether bought new or used, the Ninja 400 represents fantastic value. Buying new offers the full warranty and the latest options, while a used model, thanks to its low depreciation and robust reliability, provides even greater savings. When buying used, prioritize models with ABS for enhanced safety. The KRT Edition offers a visually striking aesthetic, but mechanically, it's identical to the standard trim, so choose based on your visual preference and budget. Overall, the Ninja 400 delivers a balanced, thrilling, and sensible ownership experience for almost anyone.
Cathleen V
Cathleen is an exceptional freelance writer covering hot topics in the automotive world from a gearhead's perspective. Her articles delve into various aspects of automotive technology and history, offering readers detailed insights into engine performance, reliability, and maintenance. Through her engaging and informative writing, Cathleen provides valuable information to automotive enthusiasts and consumers alike, helping them make informed decisions about vehicle maintenance and purchases.