2018 KAWASAKI NINJA 400
FULL TEST
P88
Come to think of it, there's no
electronic rider aid whatsoever aside
from the optional ABS model, so it's
all about seat-of-the-pants feel, rather
than electronic intervention, when try-
ing to go fast on the track.
A good mate of mine, Road Racing
World's Chris Ulrich, himself a former
AMA Superbike weapon, said it best
about the engine when we pulled in
What's it got, mister?
It's not simply a case of boring
out the 300's cylinders to make
the new Ninja 400 what it is. The
parallel-twin engine has been
extensively overhauled, so let's
dive into the changes.
MOTOR
• Bore has been widened by
8mm and stroke lengthened by
2.8mm to give the 399cc capacity
change.
• Kawasaki has fitted a new
downdraft intake, which they say
is the shortest and most direct
route for the incoming air into the
all-new airbox. The downdraft
intake layout is claimed to improve
cylinder filling, especially at high
rpm, and helps eliminate space
under the seat and thus make it
easier for shorter riders to reach
the ground.
• Airbox itself has been increased
by 1.1 liters to 5.8 liters, with the
top of the airbox more rigid than
the 300's, so as to get more
intake note under acceleration.
• Unlike the 300, the 400 has
unequal-length intake funnels to
help smooth out dips in the torque
curve.
• Twin 32mm throttle valves are the
same size as the outgoing 300.
• Intake and exhaust valves
measure 27.7mm and 23.5mm,
repectively.
• Forged cams are lighter than
the 300's.
• Compression ratio has been
upped from 10.6:1 to 11.5:1 thanks
to a flatter piston crown.
• Cylinder is canted forward 20
degrees to reduce overall height
and help with weight distribution.
• Flywheel has been lightened to
help the motor spin up faster.
• The radiator fan has a new
design that helps funnel air
directly downwards to the road,
which reduces the overall heat
coming off the engine that
reaches the rider.
• The slip and assist clutch has
reduced in diameter from 139mm
to 125mm, which results in a
much lighter pull at the lever than
with the 300 clutch.
Check out the radiator
fan directing heat
towards the ground,
rather than fill the rider
up with excessive heat.
Smart.
