Two years ago we said that if Kawasaki built a lower, lighter and sleeker bike that they could win the “2016 MXA 450 Shootout.” But even though the 2016 Kawasaki KX450F was a lighter, thinner and
lower, the MXA wrecking crew reneged on the deal for it to win the 2016
shootout. Why? The 2016 Kawasaki engine had the bad manners to ping
when it got hot and pop on deceleration whenever we backed off from
full throttle. We were lean and we knew it, but the problem could only be
solved with Kawasaki’s $700 reprogramming tool. So, most people relied
on the black (rich) plug-in coupler. The pinging stopped, but the overall
power was reduced.
For 2017 the Kawasaki KX450F comes with the mapping it should have
had in 2016. The better EFI mapping made the 2017 KX450F feel stronger
in transition off the bottom and into the middle. It wasn’t any more powerful than it was in 2016, but now you can utilize the power to its fullest.
HOW DOES THE KX450F RATE IN THE MAJOR CATEGORIES?
Power output: Good. Kawasaki has also had a reputation for building
powerful 450cc engines. There were years when the Kawasaki KX450F won
the MXA shootout on the sheer superiority of its engine, despite the rest of
the flawed machine. That was the past. For 2017 the KX450F has a solid,
linear, easy-to-use powerband. It doesn’t jerk your arms out of the sockets
like the fabled 2012 KX450F engine. This is a new-school Kawasaki. Gone
is the brutal hit, and in its place is an amazingly smooth engine that allows
you to go fast with less effort. We like this engine.
Suspension: Good. These are really good air forks. We never thought
we would ever say that about Showa TAC forks. Whether we were setting
them up for an AMA Pro or a portly Vet Novice, we got them in the sweet
spot quickly (in sharp contrast to the SFF TAC forks on the 2017 Suzuki
RM-Z450). If you take the time to learn the KX450F’s Showa SFF-TAC air
forks, you will find that they are not as scary as they have been made out
to be. As for the rear shock, Kawasaki lengthened the pull rods by 0.5mm,
added a more progressive rising-rate bell crank, which will retrofit on the
2016 model, and increased the opening in the swingarm where the shock
goes through for mud clearance. The shock worked well from day one,
and although we went out on several settings and ran the race sag at a
relatively low 105mm, we liked the improvements to the rear suspension.
All in all, we liked Kawasaki’s suspension setup.
Handling: Very good. Previous KX450Fs were upright, cranky bikes
that required handlebar input to make them turn. We never liked them
and always changed the shock linkage, triple-clamp offset and setup to try
to compensate for the KX450F’s quirkiness. Not so with the 2017 KX450F.
It’s night and day better than the old-school Kawasaki. It wanted to turn
and felt light, agile and quick (words we never used to describe a KX450F
Brakes: Fair. The KX450F 270mm brakes were nothing special, and they
still have the same problem they had 20 years ago. The brake fluid has to
be changed early in the KX450F’s life, because the brakes feel mushy off
the showroom floor.
Clutch: Fair. The best fix for the KX450F clutch is to install a Hinson.
When we roll the bike out of the shop for the first test run, we have already
installed stiffer Pro Circuit clutch springs.
Weight: Very good. In the pyramid of weight, the 2017 Kawasaki
KX450F ranks third lightest overall but first among Japanese-built bikes.
At 231 pounds, the KX450F is 2 pounds lighter than the CRF450, 7 pounds
lighter than the YZ450F and 9 pounds lighter than the RM-Z450. It goes
without saying, but we will say it anyway—the KX450F weighs 9 pounds
more than the KTM 450SXF and 7 pounds more than the Husqvarna FC450.
Horsepower: Fair. The 2017 Kawasaki KX450F is not a powermonger.
Its 55. 43 horsepower places it behind the KTM, Husky, Honda and Yamaha
on the dyno runs. Its 35. 79 foot-pounds of torque doesn’t light up any
Roman candles, either, but this is still a very good powerband—not because
of the power it makes, but because of the way it delivers that power to
2017 KAWASAKI KX450F CONCLUSION
For years we always thought of the KX450F in terms of its powerband
and nothing else, because nothing else stood out. For 2017 the changes to
the mapping, fork valving, triple clamps, shock spring, rising rate and seat
base brought the new-generation KX450F into sharper focus. It’s a bike for
everyman not just Pros. It makes motocross easier to do. The 2017 KX450F
is as far away from its previous relatives as a bike could get.