Kawasaki Ninja 400 (2018-2022) — Maintenance Specs

Kawasaki's entry-level sportbike replaced the Ninja 300 in 2018 with a 399 cc parallel twin, a slipper clutch and a chassis light enough to make it the class benchmark. It is cheap to maintain: 2.0 L of ordinary 10W-40 JASO MA oil with the filter, a single NGK LMAR9G plug, and a 14 L tank. The 2020 manual documented here covers the whole 2018-2022 EX400G/H run, which changed only in paint and minor suspension tweaks after 2020. Owners should watch the 20-30 mm chain slack spec and the modest 28/32 psi tire pressures that suit its small tire carcasses.

Quick specs

Oil capacity (with filter) 2 L2.1 US qt, when filter is removed

Oil capacity (without filter) 1.6 L1.7 US qt, when filter is not removed

Oil type API SG, SH, SJ, SL or SM with JASO MA, MA1 or MA2

Oil viscosity SAE 10W-40

Front tire pressure (solo) 28 psi200 kPa, cold

Rear tire pressure (solo) 32 psi225 kPa, cold

Spark plug NGK LMAR9G

Spark plug gap 0.7-0.8 mm0.028-0.031 in

Maintenance schedule

Specification	Value	Source
Engine oil & filter	first 1,000 km (600 mi), then every 12,000 km (7,600 mi) or 1 year	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)

Fluids & capacities

Specification	Value	Source
Oil capacity (with filter)	2 L2.1 US qt, when filter is removed	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Oil capacity (without filter)	1.6 L1.7 US qt, when filter is not removed	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Oil type	API SG, SH, SJ, SL or SM with JASO MA, MA1 or MA2	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Oil viscosity	SAE 10W-40	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Coolant capacity	1.3 L1.4 US qt	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Brake fluid type (DOT)	DOT 3 or DOT 4 (front), DOT 4 (rear)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Fuel capacity	14 L3.7 US gal	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)

Torque specs

Specification	Value	Source
Oil drain plug	30 Nu00b7mengine oil drain bolt (3.1 kgfu00b7m, 22 ftu00b7lb)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Rear axle nut	98 Nu00b7maxle nut (10 kgfu00b7m, 72 ftu00b7lb)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)

Electrical

Specification	Value	Source
Battery	12V 8Ah (10HR)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Headlight bulb	LED (high/low)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Spark plug	NGK LMAR9G	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Spark plug gap	0.7-0.8 mm0.028-0.031 in	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)

Tires & wheels

Specification	Value	Source
Front tire size	110/70R17M/C 54H	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Rear tire size	150/60R17M/C 66H	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Front tire pressure (solo)	28 psi200 kPa, cold	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)
Rear tire pressure (solo)	32 psi225 kPa, cold	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040)

Official manual

Owner's manual on Kawasaki official site

Opens the manufacturer’s official website in a new tab.

Frequently asked questions

How much oil does a Kawasaki Ninja 400 need?

1.6 L for a drain-only change, 2.0 L with the filter, 2.3 L total dry capacity.

What is the Ninja 400 tire pressure?

28 psi front and 32 psi rear when cold.

What spark plug does the Ninja 400 use?

NGK LMAR9G gapped at 0.7-0.8 mm.

Ninja 400 chain slack?

20-30 mm, checked on the sidestand per the manual.

Sources

Value	Source	Checked
Oil capacity (with filter): 2 L	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Engine Oil section, p. 108)	2026-11-03
Oil capacity (without filter): 1.6 L	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Engine Oil section, p. 108)	2026-11-03
Oil type: API SG, SH, SJ, SL or SM with JASO MA, MA1 or MA2	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 28)	2026-11-03
Oil viscosity: SAE 10W-40	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 29; Engine Oil section, p. 108)	2026-11-03
Coolant capacity: 1.3 L	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 29)	2026-11-03
Brake fluid type (DOT): DOT 3 or DOT 4 (front), DOT 4 (rear)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 30)	2026-11-03
Fuel capacity: 14 L	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 30)	2026-11-03
Engine oil & filter: first 1,000 km (600 mi), then every 12,000 km (7,600 mi) or 1 year	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Periodic Maintenance Chart)	2026-11-03
Oil drain plug: 30 Nu00b7m	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Engine Oil section, p. 108)	2026-11-03
Rear axle nut: 98 Nu00b7m	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Wheel section, p. 122)	2026-11-03
Battery: 12V 8Ah (10HR)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 30)	2026-11-03
Headlight bulb: LED (high/low)	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 30)	2026-11-03
Spark plug: NGK LMAR9G	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 28)	2026-11-03
Spark plug gap: 0.7-0.8 mm	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 28)	2026-11-03
Front tire size: 110/70R17M/C 54H	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 30)	2026-11-03
Rear tire size: 150/60R17M/C 66H	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Specifications, p. 30)	2026-11-03
Front tire pressure (solo): 28 psi	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Tires section, p. 132)	2026-11-03
Rear tire pressure (solo): 32 psi	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Tires section, p. 132)	2026-11-03
Chain Slack: 20-30 mm	2020 Kawasaki Ninja 400 (EX400G/H) Owner's Manual (Kawasaki Owners Center / KTIVS e-book, US, item 99803-0040) (p. Drive Chain section, p. 120)	2026-11-03

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