Jay Clark, project bike builder extraordinaire, is an expert
at uncovering good deals. He’s equally good at restoring
misused and neglected motorcycles to like-new condition.
The 2005 CR125 that you see on these pages was transformed from an old warhorse into a show pony. A dull
aluminum frame, oblong wheels, bent handlebars and
thrashed plastics indicated that the bike was ridden hard
and put away wet many times. Ten years of thrashing
weren’t kind to the CR125. It took elbow grease and deep
pockets to return the bike back to its original condition;
however, Jay Clark and Vertex Pistons set their sights on
bolstering performance rather than merely returning the
CR125 to stock condition.
Money talks, and while it would have been easy to
simply swap out worn parts for shiny new components,
taking that approach might have resulted in serious
consequences. Why? Would you hop on an unproven bike,
click top gear and hit the biggest jump on the track?
We hope not. It’s important to inspect every part and go
through a used bike with a fine-tooth comb. That’s exactly
what Jay Clark did with the 2005 CR125.
Tom Hanks, in Forrest Gump, famously quipped, “Life is
like a box of chocolates; you never know what you’re going
to get.” That holds true for a used bike. Jay Clark pulled
out the engine, checked the frame for cracks, sent the
suspension out to be serviced, and inspected every nook
and cranny for signs of wear. The parts list grew long,
especially after Jay tore apart the engine. The stock crank
and cylinder were salvageable, but the CR125 was in
desperate need of a new piston kit. It was also in need of
more power. Clark shipped the cylinder and head to Terry
Varner while dropping in a Vertex Pro Replica piston kit
(ring, pin and clips) that fed off 100-octane gas and Klotz
R- 50 two-stroke pre-mix.
In stock trim, the 2005 Honda CR125 had the heart of a
feeble dog; however, what the engine lacked in pure horsepower, it made up for with incredible handling. Such a
combination is the norm, because a slow engine allows the
chassis to keep up. We didn’t expect Jay Clark to throw
caution to the wind by pumping up the powerband at the
cost of ruining the handling traits. Varner massaged the
engine to let the bike breathe. An FMF pipe and silencer with a Moto Tassinari V-Force reed cage were bolt-on
power. Other modifications to the 2005 Honda CR125 were
made as necessary, such as new Tusk wheels to replace
the bent stock rims and a Regina chain with Renthal
sprockets. Jay Clark indulged in certain areas—the Cycra
plastics and Moto Seat cover come to mind—but in Jay’s
defense, he wanted to make the CR125 stand out.
When all was said and done, Jay Clark had about $2500
invested into the $900 Honda CR125. For $3400, he built a
race-ready two-stroke capable of winning the Novice class.
Ten-year-old technology, such as conventional forks and a
carburetor, seems antiquated in an age where electronic
fuel injection, air forks and plug-in maps are the norm, but
newness was never meant to be the CR125’s charm. Clark
proved that he could save a thrashed bike on the brink of
oblivion for half the cost of a brand-new 125cc two-stroke.
That, in essence, is what this bike build is all about. Great
deals are buried deep within Craigslist’s unending network
of web pages, but it will take patience and resolve to find
them. Take solace in knowing that your dream bike is out
there somewhere. As the saying goes, “One man’s trash is
another man’s treasure.” Truer words were never spoken
about the Vertex Pistons’ 2005 Honda CR125 two-stroke
For more information, please call (515) 270-2302 or visit