So, did the project feel like it had been punched out or
downsized? Neither. First of all, it’s nothing like a 450. Not
at all. And, a 270 might be only 3mm bigger across the piston than a 250, but it feels very different. A 270 is its own
beast. The midrange power is an outstanding improvement,
and that makes the Suzuki a much less intense ride. With
the average 250F, it isn’t a lack of peak power that keeps
older riders away; it’s a lack of forgiveness. You have to
keep it screaming all the time and be careful not to slip
down too many notes on the power keyboard. If you let it
drop, you stop. Not so with a 270. You can actually ride
it out of a low-rpm hole without a downshift. But you still
have to shift, which is why it’s not a 450 substitute. For any
given turn, you have to remember to click it down just as
many gears as you would a 250 if you want to go fast. But
if you screw up, you won’t get passed.
We knew the midrange power would improve before
we started. The real measure of success
was how well we were able to
minimize the negatives. Would it
rev? Would it stall? Would it start?
The answers are yes, no and some-
1.) Excellent midrange power. 2.) Loss of top-end revs.
3.) More frequent stalling. 4.) Harder starting. In case
you’re keeping score, that’s three negative results versus
one positive. In most cases, though, that one positive is
enough to cancel out everything else. We, of course, would
prefer no negatives, so we kept going with the motor. Hot
Cams’ Stage 2 intake and exhaust cams were dropped in
and amazingly needed no change in shim sizes. The idea
was to replace lost revs. To deal with the stalling and starting issues, we turned to Wade Wilcox at Injectioneering.
Wilcox performs precision throttle-body modifications,
and his work can be found on many pro-level Supercross
bikes. Most of his tweaking is done on the butterfly valve
and is painstakingly precise. Frankly, we don’t understand
why anything as primitive as a butterfly valve is still used
on 21st century fuel-injection systems when they were
considered obsolete on carburetors built 20 years ago, but
Wade gets the most out of them.
Everything around the Suzuki’s motor still ranks at the
top of the 250F class. Nothing turns better, and the suspension is excellent. We wanted minimal off-road capability, and we addressed that primarily with suspension
modifications from RG3 and a new wheelset from Warp 9,
complete with Pirelli Scorpion off-road tires (an 18-incher
in the rear).
We toyed with the idea of a fully automatic
Rekluse clutch but settled for just the basket. We had faith that our stalling issue
would be handled.
Warp 9 makes affordable wheels for most dirt bikes. We used
Pirelli Scorpion MX Extra X off-road tires.
Flu Designs did an
outrageous job of
making our RM-Z look