⟲ 360° — drag meThe facts.
| Brand | Akrapovic |
|---|---|
| Part number | S-K4SO6-APC |
| Fitment | Kawasaki Ninja 400, Z400, Ninja 500 (2018–2026) |
| Line | Slip-On Line (Carbon) |
| Material | Carbon fibre |
| Weight | 1.69 kg (stock 4.08 kg, saving 2.39 kg / 58.6 %) |
| Power | 46.1 PS (stock 44.3 PS, gain 2.4 PS at 11,000 rpm) |
| Torque | 36.1 Nm (stock 35.8 Nm, gain 1.1 Nm at 3,300 rpm) |
| Noise insert | Removable insert included |
| Road approval | None — track use only |
DescriptionThe whole story▼
2.4 horsepower on a 44 PS engine — over five per cent, which is a larger proportional gain than any litre bike in this catalogue manages from a slip-on. Small engines have more to give back, because the standard exhaust took proportionally more away.
Key Features
- 2.4 PS more at 11,000 rpm, peak output rising from 44.3 to 46.1 PS
- 1.1 Nm more at 3,300 rpm — very low in the range
- 1.69 kg against the standard 4.08 kg: 2.39 kg and 58.6 per cent less
- Carbon fibre construction
- Removable noise insert included
- Twenty minutes to fit
- Covers the Ninja 400, the Z400 and the Ninja 500
Three Names, One Platform
Kawasaki launched the Ninja 400 and its naked sibling the Z400 in 2018, then enlarged the engine to 451 cc for 2024 and renamed them Ninja 500 and Z500. The exhaust mounting carried over unchanged, so one silencer covers all of them from 2018 to 2026.
These are A2 machines, and among the most common first big bikes in Europe. A slip-on that fits nine model years is a useful thing to stock.
Gains at Both Ends
1.1 Nm at 3,300 rpm and 2.4 PS at 11,000 — one just off idle, one near the limiter. That is unusual: most slip-ons lift one part of the curve and leave the rest alone.
On a 400 twin ridden by someone learning, the low-rev figure is the one that matters day to day. The peak is what shows on the dyno sheet.
Twenty Minutes
The Ninja 400's silencer is held by a clamp and a single bracket bolt, reachable without removing bodywork. It is among the easiest exhaust changes on any motorcycle in this catalogue.
Not the Ninja 400 of 2024
Kawasaki kept the Ninja 400 name in some markets after introducing the 500, which makes model-year checking essential. The exhaust mounting is the same across the whole run, so this silencer fits either — but knowing which bike you have matters for everything else you might order.
An Insert Comes With It
The removable noise insert is included. Fitted, the exhaust is quieter and closer to what a club circuit will accept; removed, it is at its loudest. Neither state carries a road approval.
Nine Model Years
2018 to 2026 on one part number, across an engine change from 399 cc to 451 cc and two model names. Kawasaki left the silencer mounting alone throughout, which is unusual and makes this an easy part to buy for a used machine.
Carbon on an A2 Bike
A carbon silencer costs a noticeable fraction of what a used Ninja 400 is worth, and that is worth saying out loud. It is bought by owners who intend to keep the machine, or who will move the part onto the next bike — the mounting is common enough across Kawasaki's range that this is realistic.
Fitment and Compatibility
S-K4SO6-APC covers the Kawasaki Ninja 400 and Z400 from 2018 and the Ninja 500 from 2024, through 2026.
Road Approval
None. This product does not meet emission compliance requirements for street or highway use.
Specifications
- Part number: S-K4SO6-APC
- EAN: 3831113557474
- Fitment: Kawasaki Ninja 400, Z400, Ninja 500 (2018–2026)
- Line: Slip-On Line (Carbon)
- Material: carbon fibre
- Weight: 1.69 kg (stock 4.08 kg, saving 2.39 kg / 58.6 %)
- Power: 46.1 PS (stock 44.3 PS, gain 2.4 PS at 11,000 rpm)
- Torque: 36.1 Nm (stock 35.8 Nm, gain 1.1 Nm at 3,300 rpm)
- Noise insert: removable, included
- Installation time: approx. 20 minutes
- Road approval: none — track use only
- Country of manufacture: Slovenia
FitmentWhich bikes this fits▼
- Kawasaki Ninja 400 and Z400 (2018–2023)
- Kawasaki Ninja 500 and Z500 (2024–2026)
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