VOL. 52 ISSUE 28 JULY 14, 2015 P49
sacrificing any power and they
have seemed to have met that
goal. The Yamaha still yanks
hard when you first open up the
throttle but not quite as dramati-
cally as before, which, really is
a good thing—at least for most
people. Justin Barcia might like
the previous harder hit better, but
he's Justin Barcia and we're not.
Very few are. The new power
delivery, which makes the bike
easier to ride, should appeal to a
wider range of riders. From mid
range on up, the YZ feels just like
it did before and that is F-A-S-T!
No surprises here.
Yamaha did change the YZ's
ECU base mapping a bit from the
2015 YZ; it's said to be richer in
certain areas. Of course, the YZ's
ECU mapping can be easily al-
tered—by you—via Yamaha's GYTR
Power Tuner (sold separately for
$279.95). On this day, we stayed
with the stock mapping. The
GYTR Power Tuner is a very use-
ful tool; it might not be as simple
to use as swapping out couplers,
but it's pretty darn close, and far
more "fine-tunable." It's worth
every penny. The YZ has plenty
of power on tap—that's not the
question—but getting that power to
the ground efficiently can be (with
all 450s actually), and the Power
Tuner will help make that happen
with the YZ.
Other changes to the YZ's
motor are relatively minor.
Yamaha made revisions to the
clutch boss and shift stopper
arm to provide smoother clutch
engagement and more precise
feel. Yamaha says that some
tweaking to the five-speed trans-
mission also results in improved
shifting while under a load and
reduced chances of missed-
shifts between first and second
gears. All we can say so far is
that the Yamaha nailed every
shift all day long on our first
ride, but we didn't have any real
gripes with last year's tranny.
Yamaha also made improves
to the water-pump impeller to
improve "pressure distribution."
We assume this means more
efficient cooling.
Yamaha, however, did make
a fair amount of changes to the
