Q: FIRST AND FOREMOST, IS THE 2015
KX450F BETTER THAN THE 2014 KX450F?
A: After four years of relative status quo on the
KX450F front (save for the Kayaba PSF air fork on the
2013–’ 14 model), the 2015 model gets a heap of love. But
does the love result in a better bike? Yes, with some
Q: WHAT DID KAWASAKI CHANGE ON THE
A: The KX450F engine hasn’t changed much over
the last half a decade—and that is a good thing. The
Kawasaki engineers played camshaft roulette in 2011,
2012 and 2013, but that was really a one-year change
(2012) that they rectified in 2013.
For 2015, Kawasaki made three changes to the
(1) Traction control. Although traction control has
been illegal under AMA rules for the last three decades,
the rules were conveniently changed just in time for the
( 2) Bridge-Box piston. The new piston features short
skirts with reinforcing ribs to go along with a revised
combustion dome shape. This change is more for
durability than performance.
( 3) Compression ratio. Compression was raised from
12.5:1 to 12.8:1 as part of the new structurally stronger
Bridge-Box piston upgrade.
Q: IS THE 2015 ENGINE MORE POWERFUL
THAN THE 2014 ENGINE?
A: We don’t think so. Most MXA test riders felt that
the 2014 engine pulled harder off the bottom. The
faster the test rider, the more they preferred the 2014
powerband. The power differences are related to the ECU
mapping and can be reprogrammed out.
It should be noted that the 2015 KX450F’s powerband
is still a thing of beauty. It is smooth down low, rolls on
with authority and is an awesome race engine.
. Q: DID WE HAVE ANY ENGINE ISSUES?
A: Yes. We had several qualms about the KX450F
Visually the KX450F has stayed frozen in time almost
since its inception, but technically it gets updates almost
every year. For 2015 the mods include a bigger front
brake, new air forks, traction control and rear axle nut.