BEFORE THE BORE: Suzuki won our 2012 250F
shootout, despite being unchanged since the previous year.
For that matter, it also won the 2011 250F shootout, but for
different reasons. In 2011, it was the best in every category.
It made the best power, had the best suspension and it had
the best handling. By 2012, it had been surpassed in all
those categories, but not by any one bike. By being so
good in so many ways, the Suzuki emerged as a surprising
winner. But, it needs attention. If that attention isn’t coming
from Suzuki, it might as well come from us.
THE PARTS: The Cylinder Works kit with the Vertex piston gave the Suzuki a 3mm increase in bore, bringing it to
80mm. The Suzuki’s stroke is 0.2mm shorter than the
Honda’s, so the end result is 269.4cc. It got both intake and
exhaust cams from Hot Cams (Stage 2). For the Suzuki’s
EFI system, we looked to Bazzaz because of that company’s close work with Yoshimura and the factory Suzuki race
team. The Z-FI kit comes with a fully reprogrammable black
box and defaults that have been set up based on extensive
dyno testing (presumably on a motor with stock displacement). We installed a Uni filter with the air-filter cage from
the Suzuki RM250 two-stroke because it has no backfire
screen, and we topped off the motor with a Factory 4.1
RCT Ti muffler and Megabomb header.
Suzuki won our 2012 250 MX comparison
after a knockdown, drag-out fight with the
Kawasaki. Factory Connection set up the
RM-Z’s suspension for our 270 bash.
RESULTS: When you start off with such a great bike, it’s
tough to mess things up. We loved the RM-Z270 just like we
loved the RM-Z250. What’s not to love? We started off with a
powerful, well-suspended bike and made it more powerful
across the board. The kit helped the most right in the middle.
There might have been some benefit at the very bottom too,
but frankly you never ride that low in the rev range, at least
not on a motocross track. On top, the peak power arrived
earlier than stock, but the over-rev was fairly long and flat. If
you wanted to stretch a gear without shifting, you could get
away with it; the Suzuki wouldn’t fall on its face. In the end,
the big-bore kit was a distinct improvement over stock, but
the Suzuki didn’t get quite as much benefit as the Honda.
It pays to use good
SECOND PLACE: SUZUKI RM-Z270
Suzuki didn’t do
anything to its 2012
RM-Z250, so we did.