The GET GP1-EVO is hidden behind the front number plate.
The team tailors the map settings to Austin’s liking. It’s a
handy device for fine-tuning engine performance.
Take a close look at the clutch arm on Politelli’s YZ250F. It
has been shortened several millimeters for better feel at the
lever. The 51Fifty team does this modification at their shop.
This isn’t your average YZ250F engine package. There are a
host of high-performance GYTR parts, along with the team’s
race-spec mods. It’s a mean machine.
THE BIKE SETUP
The ergonomics on Austin’s bike only vary slightly from
the stock YZ250F. At 6 feet, Austin is taller than the average 250 rider. With the Yamaha having a somewhat small
cockpit, Dan Worley at SDI made Austin custom handlebar spacers that raise the bars 5mm higher than stock.
This gives Austin better leverage and improved ergonomics for his height. The Works Connection clutch perch
was reworked for more leverage by shortening the push
lever. Additionally, Austin runs his rear brake lever fairly
high so he can keep back on the bike in an aggressive
position while gaining access to the rear brake pedal.
THE 51FIFTY POWERPLANT
A majority of AMA Supercross race bikes we test are
ticking time bombs. From the moment a factory engine
is built, it is placed on a clock that counts down the
minutes until it is rebuilt again. Typically, a factory race
engine has a two-hour lifespan on the Supercross circuit.
The 51Fifty YZ250F engine was built for reliability. The
MXA wrecking crew got the green light to put as much
time as we needed on the 51Fifty machine, but don’t
mistake Politelli’s engine for the stocker. With the help
of its programmable GET GP1-EVO black box, the engine
sings at a high-revving 14,000 rpm. That’s great for
Austin, because he prefers to run high in the rpm range.
The emphasis on top-end power made the 51Fifty YZ250F
feel a little sluggish from bottom to mid, especially for a
Supercross setup, but you gotta give to get—and they got
tons of top.