⟲ 360° — drag meThe facts.
| Brand | Akrapovic |
|---|---|
| Part number | S-K4SO7-HRT |
| Fitment | Kawasaki Ninja 400 and Z400 (2018–2024) |
| System type | Slip-on silencer |
| Materials | Titanium outer sleeve |
| Weight | 2.78 kg (stock 4.08 kg, saving 1.3 kg / 31.9 %) |
| Power | 45.8 PS (stock 44.3 PS, gain 1.5 PS at 10,300 rpm) |
| Torque | 36.4 Nm (stock 35.8 Nm, gain 0.8 Nm at 8,300 rpm) |
| Installation | Approx. 20 minutes |
| Road approval | EC type approval and ECE type approval |
DescriptionThe whole story▼
One and a half horsepower at 10,300 rpm on a 399 cc twin. The Ninja 400 is a small sportbike built to be revved, and this system finds its gain exactly where the engine wants to be — not in a mid-range that a 400 barely has.
Key Features
- 2.78 kg against the standard 4.08 kg: 1.3 kg and 31.9 per cent less
- 1.5 PS more at 10,300 rpm, peak output rising from 44.3 to 45.8 PS
- 0.8 Nm more at 8,300 rpm
- Titanium muffler outer sleeve
- Twenty minutes to fit, removable noise insert supplied
- Fits the faired Ninja 400 and the naked Z400
- EC and ECE type approved, A2 restriction untouched
A Bike Where 1.3 Kilograms Is a Real Share
The Ninja 400 weighs 168 kg ready to ride. Removing 1.3 kg is close to one per cent of the whole motorcycle, taken from the highest and furthest-back point, and on a machine this light a rider notices it in slow-speed handling and in how quickly the bike falls into a corner.
That is also why the standard silencer is heavy: Kawasaki built the Ninja 400 to a price, and the exhaust is where the money was not spent. It is the same pattern seen on every affordable motorcycle in this catalogue.
A2 and the Certificate
The Ninja 400 and Z400 sit inside the A2 licence class, and most of them are ridden by people on a restricted licence. A non-approved exhaust on such a machine puts the restriction certificate and the insurance cover in question — a disproportionate risk for a part at this price.
This one carries EC and ECE type approval and changes neither. The removable noise insert lets the sound be kept close to standard for an inspection.
Ninja 400 and Z400
Kawasaki sells the same 399 cc parallel twin in two bodies: the faired Ninja 400 and the naked Z400 with a wide handlebar and an upright seat. The frame and the exhaust mounting are shared, so one silencer serves both.
What Stays Standard
The header, the catalytic converter and the engine management are untouched, no remapping is required, and the original silencer bolts straight back on. On a first big bike that will be sold on within a few years, having the standard parts in the box is worth real money.
Installation is twenty minutes. The Ninja's lower fairing does not have to come off — the silencer is reachable from below with the bike on its side stand.
Fitment and Compatibility
S-K4SO7-HRT covers the Kawasaki Ninja 400 from model year 2018 through 2024 and the Z400 from 2019 through 2024. For the Ninja 500 and Z500 that replaced them, the corresponding part is S-K5SO1-HRT.
Road Approval
EC type approval and ECE type approval, with the certificates supplied and downloadable here. The silencer is a legal replacement part for road use in the European Union and does not affect an A2 restriction.
Specifications
- Part number: S-K4SO7-HRT
- EAN: 3831126411114
- Fitment: Kawasaki Ninja 400 (2018–2024), Z400 (2019–2024)
- System type: slip-on silencer
- Outer sleeve: titanium
- System weight: 2.78 kg (stock 4.08 kg, saving 1.3 kg / 31.9 %)
- Power: 45.8 PS (stock 44.3 PS, gain 1.5 PS at 10,300 rpm)
- Torque: 36.4 Nm (stock 35.8 Nm, gain 0.8 Nm at 8,300 rpm)
- Noise insert: included
- Installation time: approx. 20 minutes
- Road approval: EC type approval and ECE type approval
- Country of manufacture: Slovenia
FitmentWhich bikes this fits▼
- Kawasaki Ninja 400 (2018–2024)
- Kawasaki Z400 (2019–2024)
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Measure your head circumference about one centimetre above your eyebrows and compare it with the size chart on this page. Between sizes? Choose the smaller one — the padding beds in with use.
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Most of our touring and sport helmets are Pinlock-ready and many include the insert. Check the ‘What’s in the box’ section on this page for this model.
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