Slip-on Exhaust system was installed
and we removed the airbox lid and installed
a "Dial-A-Jet" Kit for added
For added reliability, the engine would remain
stock, but the addition of a HMF slip would add
several extra ponies to our project without the
worries of a blown head gasket, which is a common
problem for modified 400EX engines. C&D Racing
also supplied us with a product called a "Dial-A-Jet"
that would help us tune the carburetor without
the hassle of changing out main jets. The Dial-A-Jet
works by adding fuel via a small tube installed
in the airboot just ahead of the carburetor, using
vacuum as a trigger.
To aid in controlling some heat issues on the
air cooled engine, we turned to CFM Performance
who sent over one of their higher capacity oil
tanks which boast an increased oil capacity.
A set of Tinner's Air Scoops were ordered and
installed to help redirect some air flow to
keep our little thumper's temperature in check.
Oversized Oil Tank
Matching aftermarket components can present
a problem as it did for us with a Pro
Armor Skid Plate & AC Nerf Bars because
they required some modifications to install
For rider safety, a set of AC nerf bars were
attached, and this is where we ran into our
first snag. We wanted to use a Pro Armor chassis
skidplate which fit perfectly, however we chose
to run the AC nerf bars simply because we already
had a set. The issue arose when installing the
nerfs in conjunction with the Pro Armor skid.
The Pro Armor skid utilizes side frame protection
towards the front engine mount, which interferes
with the AC nerf bars. We opted to get around
the issue with some simple backyard know how.
A 1 1/4 hole saw was employed to allow 2 holes
for the nerf bars to flow through.
The installation of the majority of parts used
on this project went together without issue,
which wasn’t a surprise considering the
400EX has been on the market long enough that
most issues with regards to design and fitment
have long since been made perfect. The only
real issue we encountered was with the G-Force
axle as the rear hubs seemed very sloppy on
the axle splines. This will have to be watched
carefully as we put time in to see if it will
affect our opinion of the axle and it's lower
price as compared to others on the market.
Following the basic directions included with
each product, it didn’t take anytime to
reassemble the project 400EX. It was finally
time to mount the Hiper Non-Beadlock rims, which
were mated with ITP Holeshot tires upfront for
increased steering control, and in the rear,
Hiper dual beadlocks were used with Carlisle
Turf Tamers for increased handling and traction
for the rear.
The stock fenders were also kept in place with
the addition of a new black hood scoop from
Maier MFG to replace the stock headlight assembly.
The styling resembles the 450R and we liked
how the colors would eventually flow together.
Goforitgraphics supplied us with some custom
graphics that helped add a race look to the
soon to be functional 400EX. The stock handlebars
were kept in place, along with the stock steering
stem. A Moose adjustable clutch lever soon replaced
the bulky factory lever and a set of Powermadd
handguards were installed to help deflect the