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JULY 2015 / MOTOCROSS ACTION 31
were riders on 250s in the
450 class. I thought this was
It is not illegal in Supercross
to race a 250cc four-stroke in
the 450 class, but it should be.
Why does Supercross allow
250Fs in the 450 class? First
and foremost, because they
can. They are mostly “show”
producers and don’t care about
the traditions, rules or reasons
for why any rule was written.
Conversely, a 250cc machine
is not legal in the AMA 450
Nationals. Under AMA 450
National rules, the displacement limit is 251cc to 450cc.
The Supercross promoters
juggled the AMA rule book to
read 249cc to 450cc. Allowing
250Fs in the 450 class is stupid
because the power difference
over the doubles and triples in
Supercross often spells trouble
when a 450 rider comes up on
a slower 250 in mid-air.
RACE GAS FOR LOCALS
Is it legal to run race gas
at local races? I know that
oxygenated gas is illegal in Pro
racing, but what about at the
weekly moto wars? Is VP U4.4 illegal
For Supercross and National
Championship competitions, the
AMA limits a fuel’s oxygen content
to 4 percent. VP’s U4.4 and most
oxygenated fuels have an 8-percent
oxygen content. But, it is not illegal
at most local races.
CAN YOU HEAR ME NOW?
My 2006 Honda CRF450 makes a
high-pitched squeal when I start it
up, but the noise goes away once the
engine warms up. What causes this?
Lack of oil in your gearbox causes
it. When the engine oil is too low,
the kick-starter idler gear runs dry
and whines. You need to add oil in
your gearbox, but there is one caveat:
the engine-oil check hole on the
2006 CRF450 is about 200cc short on
oil. The only real fix is to drain the
transmission and pour in the correct
amount from the owner’s manual.
LIFE IN A BOTTLE
I’ve recently switched back to
riding a two-stroke (2009 YZ250) and
was wondering how long should I
keep premixed gas before mixing a
fresh batch. Also, how long does a
bottle of the actual premix oil last?
It depends on where you keep it.
If you keep your gas in a plastic gas
can, it is good for two weeks at the
most. If you keep it in a metal gas
can, it will last significantly longer.
As a rule of thumb, the MXA wrecking crew tries to mix a new batch
of two-stroke oil up every other race.
As for the premix oil itself, as long
as the two-stroke oil has been kept
in unopened containers in a cool,
dry and dark place, it can last for
many years. Once you open a bottle
of two-stroke oil, you create an air
pocket inside the bottle (where the
oil you poured out used to be). This
trapped air pocket contains moisture
(how much depends on the humidity
on the day you opened it up). Even
though you put the cap back on, the
moisture will contaminate the oil in
around two months.
HOW OLD IS TOO OLD?
As I get older, I regret never
having raced the AMA Nationals.
When I was younger, I believe that I
had the speed to make the top 20—
maybe not much better than 20th,
but still I wish I had tried. Although
slower and older now, I still would
like to race a National. Are there
any age limits?
No, there are no age limits,
although after the age of 50 an
AMA Pro rider has to have an
EKG performed and fill out a more
detailed medical exam. Chad Reed is
the oldest AMA Supercross winner at
33 years old, and the late Adolf Weil
raced the GPs competitively until he
was almost 40. There was one rider,
Ed Foedish of Arizona, who signed
up for two AMA 450 Nationals last
year at the age of 50. He didn’t
qualify for the 40-man mains, but
then again, neither did a lot of