BEFORE THE BORE: Honda has a great 250F, but it’s
never been the best. For 2012, the CRF250R got a few
changes, including a smaller throttle body and new linkage. Both were improvements. The bike made more low-end power without any real loss on top, and the handling
settled down considerably. The Honda’s best feature is
that it feels light and easy to handle. Its worst feature is
its lack of distinction in the horsepower department. It’s
certainly not slow, but horsepower is critical in this class.
In our original 250F shootout, the Honda finished fourth.
THE PARTS: As with all the bikes in this story, the key
modification was a Cylinder Works big-bore kit, which
included a new cylinder, a forged Vertex piston with rings
and Cometic gaskets. In this case, the piston was 3.2mm
larger than stock, and the final displacement was
270.4cc. The Honda has a single cam, which was
replaced by a Hot Cams Stage 2 cam. The pipe was a
Factory 4.1 RCT Ti with a Megabomb header. Tokyo
Mods reprogrammed the stock ECU to deal with the
change in engine spec. The Honda also got a
MotoTassinari Air4orce air boot.
RESULTS: Not only was the CRF the most improved of
the batch, it was easily the best finished product. It made
the most horsepower and had the best power spread,
FIRST PLACE: HONDA CRF270R
The Honda CRF270 was the
clear favorite. MB-1 did the
suspension mods for our
OVERBOARD WITH OVER-BORES
starting way down low and losing virtually no revs on top.
We don’t understand why one bike would benefit from a
displacement increase so much more than the others.
We doubt it’s because the Honda has a 0.2mm-longer
stroke, but it might be because of its combustion chamber shape or because the Honda still has a comparatively large throttle body (46mm compared to 43mm on most
of the others). Either way, the CRF270R is a rocket. And
when you combine that with its already light feel, it’s a
Waking up the red beast
The Honda starts off with a very large throttle body, so it
responds well to an increase in the bore.