MONSTER MOTOR IN THREE
CT Racing has been developing the
Raptor 250 motor since its introduction
back in 2009. They currently offer three
different motor combinations. An AMA
300cc XC kit that consists of their
top-end package, along with a stroker
crank, and a custom JE 78mm big-bore
piston offering a high-torque package.
The AMA 300cc MX package utilizes
the stock crank and custom 80mm
JE piston kit, along with CT’s top-end
package offering a higher-revving MX
motor. Then, as we chose here, the
250cc International;package is a 250cc
standard bore-and-stroke package
used worldwide, including WORCS.
This package includes a choice of JE
pistons from 11.0:1, 12.0:1 and 13.0:1,
depending on fuel choices.
CT Racing CNC-ports the head and
uses their Newnen CNC contour-valve
machine to tie the porting into a five-angle radius valve job, just as many
NASCAR teams are currently doing. CT
removes the valve guides and installs
shorter guides, as the stock ones are
way too long and impede flow. CT uses
a +1mm intake valve, with the overlap
on the cam CT Racing designed.
There is not enough clearance to run
+1mm valves on both sides. CT uses a
camshaft developed by their staff and
ground to that spec by Web Camshafts.
CT has many different performance
piston configurations all made by JE
One of the cool things you’ll find on
our ride is the first-ever quick-change
clutch cover from CT Racing. To change
the clutch on the Raptor is a long, slow
process. If you have a clutch issue at
the track, you could miss a race fooling
around trying to slip in a fresh clutch.
CT will have these for sale in anodized
colors available by the time you read
this.;Check out their website for details
and colors.;While on the subject of
clutches, CT Racing has developed their
own clutch stack for the Raptor, offering
wider plates than stock and giving
more surface area to handle the added
horsepower of this little hot rod.