Ninja 400
Overview
The Ninja 400 dominated the LAMS sports bike category throughout its production. Replacing the heavier Ninja 300, it brought a larger 399cc engine, a significantly lighter trellis frame, and sharper handling. It is widely considered one of the best learner bikes ever made, offering enough performance to keep experienced riders entertained on a track day. Servicing note: the valve-clearance interval is market-specific, and the gap is wide enough to matter to your budget. Australian and New Zealand manuals (code 99986-0102, EX400GK/JK) list 42,000km. The North American manual lists 24,000km — its 2018 edition is Kawasaki part 99987-1994, and every US-market code sits in the 99987 or 99803 series rather than 99986. The same split runs through the platform: the Z400 service manual specifies 24,000km for Canadian bikes and 42,000km everywhere else, which points at North American emissions certification rather than anything mechanical about the engine. We lead with the AU figure because this is an Australian guide, but we have still not put eyes on an Australian-delivered manual — that number comes from owners quoting theirs, not from the document itself — so the field stays flagged. Check the chart in your own bike's manual before budgeting either way.
Engines & variants
399cc Parallel Twin (LAMS) LAMS approved
Under the limits as standard. No ECU or mechanical restrictions.
Compliance-plate model code:
EX400G
- NSW and Victoria both file it under the model code EX400G rather than the marketing name, and both scope the entry to 2018-on — the year this bike replaced the Ninja 300.
- All three state registers list it, so this is a lookup problem, not an approval one.
Pros
- Class-leading power-to-weight ratio for a learner bike
- Assist and slipper clutch provides an incredibly light lever pull
- Fantastic handling out of the box
Cons
- Standard seat is thin and uncomfortable on long rides
- Factory clutch springs are too soft
Known problems
unverified marks a figure we could not confirm against a manufacturer source. It is our best reading of what is published, not a checked fact — confirm it yourself before you spend money on the strength of it.
Also worth looking at
Closest in class and capacity to the Kawasaki Ninja 400.