We weren’t alarmed by the fact that our 2005 KX125 was
seized, because we intended to bore out the cylinder anyway.
The stock cylinder and oversized Wiseco piston were sent to
Millennium Technologies. The cylinder was bored out to exact
specifications in conjunction with the piston and then re-plated.
Millennium Technologies had it back to our shop in less than
We didn’t need to invest a bunch of money in the KX144
suspension, but we did have the forks and shock serviced.
Pro Circuit replaced the deteriorated fork seals, installed stiffer
fork springs, and flushed out the old gunky oil. It’s amazing
how a basic suspension service can completely change the
performance of a bike.
If you’re in the market to buy a used two-stroke, know that the
carburetor will need to be thoroughly inspected and cleaned
out. The previous owner of our KX125 failed to drain the
gasoline, causing the carburetor to become gummed up.
Once the carburetor was clean, we went up three sizes on the
mainjet to flow more fuel to the engine.
weren’t the best bikes before Kawasaki shelved their 125
two-stroke program in 2006, hence the lack of
popularity. So, we figured we could buy one cheap.
Second, we intended to bore out the cylinder and install
a 144cc kit, so it didn’t matter if the top end was frozen
up like an iceman taking a dip with the Coney Island
Polar Bear Club.
It wasn’t long before we came across a 2005 Kawasaki
KX125 on Craigslist. We met with the owner, an older
gentleman, who was looking to off-load the bike for $800.
The man bought the bike for his grandson, but he knew
very little about motocross, evidenced by the fact that he
failed to put oil in the gas before fueling the bike up. It
seized in quick fashion and was never fixed. It had been
relegated to a dark corner of the man’s garage for eight
years. Needing some extra cash, the grandfather decided
to post the bike on Craigslist. That’s where we came in.
We talked the guy down to $600 and walked away
with a mostly new, albeit aged, Kawasaki KX125.
It cost us around $1000 to make all the modifications
to the bike, including having Millennium Technologies
bore out the cylinder. We went overboard in a few areas
(the Excel rims from Dubya were an extravagance), but
in general, we tried to keep the costs down. Our KX144
project bike build is proof that anyone with a little extra
cash can own a quality motocross bike.
For more information, please visit www.wiseco.com