why the Quadzilla is so rare. Everyone
from top pros to teenage girls could
easily ride a 250cc two-stroke sport
quad. The same is not true when you
double the size of the piston. Beginning
with a 500cc two-stroke with no magic
button to pulling in a clutch that will
control major boost, a LT-500R is not
a machine for every man. Once you do
get it started, you face heavy vibration
and must deal with the effects of a
death grip on the handlebar to keep it
from getting away from you.
While we are all warm and fuzzy
over that fact that this machine exists
in such a refined form after 30 years,
this is a “daily driver” for a very special
breed of quad rider.
TOP TO BOTTOM
Duncan Racing started by getting
WHERE DOES A MONSTER LIVE?
the LT torn down to the frame before
building the machine back up to be
more potent and attractive than it
ever was when new. Some parts were
left stock, like the footpegs and front
A-arms, but those parts and many
others were chrome-plated at Pacific
Plating or polished in-house. A stock
handlebar (there is a reason that one
of the most popular modern bar bends
is QuadRacer) is used, and so is stock
plastic. Duncan believes this may be
the last full set of brand-new LT-500R
plastic in existence, but that didn’t stop
DR from trimming off the front fenders
to give the machine a sleeker look.
As you might expect with a 30-year-
old two-stroke motor, the engine
needed a complete rebuild, and it was
modified at the same time. A rebuilt
crank retains a stock rod, but the
forged piston was modified, and the
cylinder was ported as part of the Paul
Turner Racing (PTR)/Duncan Racing
(DR) engine kit. The full kit includes
a PTR pipe, billet exhaust clamp for a
leak-free pipe/silencer joint, Fat Boy
2 silencer, PTR/DR National porting,
billet-aluminum Powerhead, Pyramid
reed valve, pre-jetted Keihin 39mm
PWK carburetor and a DR clamp-on
K&N air-filter kit for stock airbox. Some
parts of the blue engine paint that the
LT-500Rs came with was freshened
up, but here more parts were polished.
The sum total of the mods is a motor
that fires pretty easily for a 500cc two-
stroke. Throttle response is crisp and
clean as well. The clutch pull is not
modern, and the shifting requires a
deliberate foot to avoid missed shifts.
But, once the engine is fired, the
Quadzilla is all about rapid, eye-water-
ing, suck-you-off-the-seat acceleration.
The Duncan-modded quad does not
disappoint. It is blindingly fast with
power that is smooth overall.
The striking blue engine in the Quadzilla looked great
new, but the cases soon grew scarred, but polishing
the aluminum fixes that problem.
Elka’s Stage 4 shocks are thoroughly modern, but
most of the other parts on this show-quality Quadzilla
could have been on any LT-500R in the 1990s.
Despite the clean and highly modified look of the Duncan
Racing Quadzilla, much of the front of the machine uses
stocks parts that are plated, polished or powdercoated.