Sometimes things seem so simple at MXA that we xpect all the pieces to fall into place without us even trying. And so it was with our Dean
Wilson project YZ450F. But, nothing is ever as easy as it
seems. We had some hoops to jump through, questions
to answer and problems to solve. Here was the Dean
Wilson YZ450F riddle and how we solved it.
WHY ON EARTH DID WE WANT TO BUILD A
REPLICA OF A BIKE THAT DEAN ONLY RACED
FOUR TIMES? It does seem odd that we chose to
build a replica of the bike that Dean Wilson started
the season on before getting a fill-in ride at Rockstar
Husqvarna. Why were we interested? We like Dean
Wilson. He is friendly, outgoing, funny and a hard
worker. More important, Dean didn’t sit at home on the
couch when the 2017 Supercross season started. He got
a Yamaha YZ450F and went to the races in what was
essentially a pickup truck. We liked the story line, especially when he did well enough to get a factory ride out
of his go-it-alone effort.
WHY DIDN’T WE BUILD A CHAD REED OR
COOPER WEBB YZ450F REPLICA? For the simple reason that Yamaha wasn’t going to give us any
works parts, secret maps or technical data to replicate
its works bikes—although we don’t know why not.
Yamaha certainly didn’t set the world on fire in the
2017 Supercross season. Only three Yamahas scored 95
percent of the points that YZ450Fs earned in 2017—and
there were hardly any Yamahas in the 450 class to speak
of, let alone test. Those three were Reed’s, Webb’s and
Wilson’s bikes. Thus, if we wanted to build a trick 2017
Yamaha YZ450F, it only made sense to choose between
one of the three—and there was one factor that swayed
us to choose Dean Wilson’s bike.
WHAT WAS THE ONE FACTOR THAT MADE
US WANT TO BUILD A DEAN WILSON REPLICA
YZ450F? Mitch Payton gave us Dean’s engine. Dean
didn’t need it once he moved to Husqvarna. Mitch
didn’t need it cluttering up his race shop. And, since
there weren’t any YZ450F riders of note after Webb and
Reed, MXA was gracious enough to take Dean’s YZ450F
engine off their hands.
WHAT WAS SO SPECIAL ABOUT DEAN
WILSON’S YZ450F ENGINE? Dean’s YZ450F engine
was special because it didn’t have any secret parts.
That made it interesting. Why? Because it could be built
by any enterprising YZ450F rider—be he a Vet, Novice,
Pro or Professional Practice Rider. It wasn’t unobtanium;
it was obtanium.
WHAT WOULD IT COST TO REPLICATE
DEAN’S YZ450F ENGINE? Once you do a little work
on a YZ450F engine, you start looking for ways to make
the powerband more manageable. Thus, Pro Circuit
didn’t go looking for beaucoup horsepower. However,
Dean’s engine did pump out 62 horses. Still, they wanted better throttle response from low to mid and a very
linear power delivery across the board.
Dean’s engine was still expensive. It cost nearly $4500:
Cylinder head porting was $649.95; Copper/Berylium
valve seats, $520; Pro Circuit-designed piston, $369.95;
Pro Circuit camshafts, $914.95; Pro Circuit intake valves,
$357.95; Pro Circuit exhaust valves, $357.95; Hinson
clutch cover, $169.95; gasket set, $68.31; NGK LMA-
R8G00 spark plug, $7.95; and an AMA-legal Pro Circuit
Ti- 6 Pro exhaust system (Dean’s pipe came equipped
with an oxygen sensor bung to help with dyno tuning),
$1064.95. We were all in at $4500—a bargain price for
an engine that was Supercross-worthy. You could add
another $1000 for a full Hinson clutch.