Husqvarna 450 on the dyno chart
on page 69 of the December issue
of Dirt Bike magazine. That’s 1.42
foot-pounds of torque per cubic inch.
That’s a lot of torque! It looks like
more than 37 foot-pounds of torque
everywhere from 5500 to 8000 rpm,
which is also very substantial. That’s
more than 1.35 foot pounds of torque
per cubic inch for the KTM/Husqvarna
450 across a very substantial range
of midrange engine speeds. The
Kawasaki KX450F, again, has somewhat of a bump in its torque curve—
from 5200 to 5800 rpm—but by 6000
rpm, the KTM/Husqvarna 450 is
making more torque than the KX450F
makes at any engine speed. And why
is the Husqvarna FC450 abruptly turning off below 3200 rpm where the
ostensibly identical KTM 450SXF is
pulling down to 2900 rpm? Don’t say
it’s the airbox. That’s an ignition map
difference for sure.
Impressive analysis considering
we didn’t publish torque numbers
for space considerations. A clever
reader can figure out torque from
the horsepower and rpm numbers
and vice versa (pound-feet x rpm /
5252 = horsepower). For those who
don’t want to do the math, we show
the torque online at www.dirtbikemag
When your engine runs cooler, your
horsepower runs at its peak. Also cool:
IceFlow protects all the metals inside your
liquid-cooled system without harming
pump seals. And beyond that, it’s non-toxic,
biodegradable and eco-friendly.
engines run cooler
non-toxic & biodegradable
It’s not just time to change your coolant.
It’s time to upgrade it.
I’m a 75-year-old rider
and have been riding since
1966. I wanted to know if
you are interested in a bike
I built. It’s based on a 2006
Honda CRF250X. I installed
a built CRF230 motor in it.
I will send a couple of pictures. Thanks for your time.
The bike is interesting.
The rider is fascinating.
MR. KIA SURVIVOR
Dear Dirt Bike,
I want to thank you and Mr. KIA
for answering my query about run-
ning my two-stroke at Baja. Heck, he
didn’t even call me an ingrown toenail
in the process! I followed the advice,
and even though the 300 has never
had much trouble with altitude sick-
ness, fattened the mixture, and, rather
than try to bring extra gas across the
border, used Star Tron and octane
boost in the Pemex fuel. The bike ran
trouble-free and didn’t skip a beat
during about 500 miles of pre-running.
The only mistake I made with it was
not gearing it up enough due to an
unfounded concern over it not pull-
ing through the deep sand. Turns out,
it actually stayed on top of it better
than the big 501 we raced and didn’t
work as hard as the four-stroke. For
anyone else who has heard the same
talk about the smokers south of the
border, it is all unfounded. Pro Moto
Limited was won on a 300 this year.
As for the race, our all-rookie (six
riders and six chasers) team hardly
set the world on fire, bringing the
bike across the line in 35 hours and
40 minutes, but accomplished our
ultimate goal of finishing. It took 50
years, but I finally got to race the
1000! Thanks again for your help.
Dear Dirt Bike,
Wow, really big torque from those
450 bikes! That looks like it’s more
than 39 foot-pounds of torque from
6500 to 7000 rpm from the 2018 KTM/
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