Fuel-injected two-strokes exist, like
this Ossa trials bike, but the Big Six
manufacturers are biding their time.
WHERE ARE THE FUEL-INJECTED TWO-STROKES?
Dear MXperts,
Why are the manufacturers that
make two-strokes—KTM, Yamaha,
Gas Gas, Husqvarna and TM—
dragging their feet on putting fuel
injection on their smokers? It would
solve the jetting issues forever and
produce even better bikes. What’s
the holdup?
The first question is, how much do
you want the price of two-strokes to
go up? The second question is, how
much weight are you willing to gain
on your two-stroke? The third question is, what’s so hard about changing a jet occasionally? The major
manufacturers have fuel-injected
two-strokes sitting in the R&D
departments that could be released
tomorrow if the world demanded
them, but let’s not put our faith in
the mob mentality of the modern
world. The current two-stroke is simple, light and relatively inexpensive.
The reason that KTM, for example,
doesn’t want to fuel inject its two-strokes is because they will gain 5
pounds, the price will go up a couple
hundred dollars and the consumer
will not be able to cure his woes
with minimal garage tools.
It’s important to note that fuel-in-
jected bikes do not produce more
power than carbureted bikes—just
the opposite. What they do produce
is a broader, easier-to-use delivery of
just the right amount of fuel for the
Xs and Os of the ECU. And, they
idle like kittens. However, motocross
bikes often need extra fuel for an
upcoming situation, and that is what
a carburetor is great at providing.
It doesn’t stream fuel electronically
via a pump; it draws fuel in via the
demands of the suction created by
the engine itself. Carbs are true-to-life
“on-demand” fuel systems.
Obviously, leaving the jetting in
the hands of a percentage of riders
who don’t know anything about
how a bike works has its drawbacks,
but once you get the jetting in the
ballpark for your track and season, it
doesn’t require an inordinate amount
of time to adjust it.
There are fuel-injected two-strokes
in the scooter, trials, watercraft, outboard engine and snowmobile marketplaces. These engines’ intake and
transfer processes handle only pure
air. The fuel is injected only after
the exhaust port closes, thus they
are more emission-standards-friendly
because no unburned fuel blows out
of the exhaust. But motocross race
bikes don’t need to be EPA-friendly;
they need to produce maximum
power. Fuel injection will come on
European offroad and dual-sport
two-strokes first, and, if we are very
unlucky, it will trickle down from
there to motocross two-strokes.
Fuel-injected motocross bikes
will come when the manufacturers
believe that they are ready for prime
time or that the market is willing
to bear the brunt of the change.
One last thing: be very careful what
you wish for, especially if you don’t
understand the ramifications. Fuel
injection will not change how you
ride your bike. It won’t make it
any cheaper, lighter or more fun. It
will just add complexity to a
machine whose saving grace is that
it is simple.
Glen Helen has the longest lap times of
all the AMA National and GP tracks.
IS THERE A RULE ABOUT HOW
LONG A LAP CAN BE?
Dear MXperts,
I want to tell Jody that I loved the
Glen Helen National track. I walked
around every inch of it, and it was
real motocross, but I heard that there
is a time limit on how long an AMA
National lap time can be. I heard it
was two minutes and that this is
why the Triple Step-Up doesn’t go
onto the REM track. Is this true?
We asked Jody, and he said that
the sanctioning body does suggest a
lap time between 2:00 and 2: 10, but
they have never stopped him from
building a track with a longer lap
time. He did, however, redesign
Glen Helen sans the REM section
to abide by the spirit of the rule’s
“suggestion.” But given Jody’s old-school sensibilities, Glen Helen is
still the longest track on the AMA
circuit, at 2: 25 a lap. That is 30
seconds shorter than the track’s
longest time when it went up onto
the REM side of the facility. Glen
Helen’s big hills presents a time challenge. Since Glen Helen has three
big hills that require a considerable
amount of time to navigate up and
down, the lower portion of the racetrack, where most of the fans are,
would have to be extremely short
to get the lap times down to the
two-minute range. Thus, the laps
at Glen Helen need to be a little
longer than the average National
track. Stepping up to the REM
section would have added another 30
seconds to the lap times. That’s too
long for our friends at MX Sports.
