2008 Apex MTX buyers should enjoy the model’s new standard
reverse. Getting the massive machine moved around in tight situations, like
parking lots and trails. Reverse also aids in getting the sled out of a jamb,
if used cautiously. While the mechanical reverse does add a few pounds to the
sled, the advantage will be worth it.
Phazer riders wondered why Yamaha left a few parts off the
2007 model, like close-off panels for the tunnel openings. All 2008 Phazers
feature the new snow panels. The panels cover the gaps and openings in the
tube-frame tunnel, where snow on the mountain models would blow through and
swirl around the rider.
Genesis 130 FI
All of the Yamaha hype this season surrounds the all-new
Genesis 130 FI triple four-stroke engine. The triple features four valves per
cylinder, a 1050cc displacement, a dry sump oil system and 11:1 compression
ratio. That means this potent engine runs on regular unleaded. The130 FI weighs
10.2 lbs. less than the Vector’s triple engine, which is just one reason why
the Nytro is so much lighter than the Vector. The 130 FI is a direct-drive
setup, so no gear reduction box is needed. The new engine has dynoed at 138 hp,
which is 15 more than the Vector engine made. It also holds its peak power
longer. The triple revs quicker than the Vector, thanks to a lighter
crankshaft, lighter cam shaft, lighter wrist pins and lighter valves. The
reduction in moving mass allows the engine to spin more quickly. Improved
intake and exhaust porting flows more air than the old triple and the new
camshaft design changes lift and duration for increased throttle response.
EBRS (Engine Braking
One inherent problem with four-stroke engines is engine
braking or compression braking. Yamaha’s Apex is a good example. When you let
off of the throttle quickly, the engine’s compression slows the crank and puts
the stops to the drivetrain. The new Genesis 130 FI engine features Yamaha’s
new EBRS, which eliminates the issue. The EBRS is essentially an air bleed
bypass that allows air to enter the combustion chamber when the throttle body
is closed off. It’s just enough air to let the engine freewheel.
Arctic Cat engineers redesigned the M Series rear suspension
for 2008. They removed the two torsion springs and rear shock and replaced them
with a single Fox Float air shock. The new skid, which also features new rail
designs and a new rear torque arm, is 8 lbs. lighter than the ’07 version.
Looking to shave a little more weight and improve the M Series
chassis, Arctic Cat updated the steering spindles on all 2008 M6, M8 and M1000
models. The race-inspired spindle is lighter than previous designs, but what’s
really important is that the spindle increases the sled’s turning radius by 10
degrees. Up to this point, Arctic Cat mountain models had one of the worst
turning radius’ in the segment. But now, they are one of the tightest.
All ’08 mountain sleds received new digital/analog gauges.
The rpm and speedometer are interchangeable between the digital readout and the
analog dial. The gauge features an odometer plus two tripmeters, clock, fuel
gauge and warning lights. Sno Pro models get a deluxe version that also
features an altimeter, heater settings, reverse engagement and other lights.
New Running boards
We have to admit, we’re more than impressed with Arctic
Cat’s new running board design on its ’08 M Series sleds. The boards feature an
open cross-grate bed design that lets snow fall through easily and prevents ice
buildup. Hot engine coolant now flows through the edge roll, which has an
improved foot grip as well. Despite weighing less, the new board design is
rigid and resists flexing and bending.
Series 5.1 Track
When it comes to track design, Polaris has never left well
enough alone. Polaris has, it seems, a new track design every year or two. 2008
is no different, though the latest version is more of an upgrade than a
redesign. Last year’s Series 5 track had lugs that overlapped one another and a
gap between the center lugs. The new Series 5.1 tack has new lugs that don’t
overlap and that have closed that centerline gap. It makes the most of every
square inch of snow it covers. And, it’s available in a new 163-inch length.
The ’07 700 CFI was a hit, especially in the western market.
That same engine technology has been applied to a larger displacement. The 800
CFI twin features the same dual-injector design and mono-block cylinders. The
engine makes a claimed 154 hp, putting it atop its class. The Cleanfire
injection technology is self-calibrating, adjusting for atmospheric changes and
engine operating temperatures.
It may be something that western riders have been doing for
years, but it’s till a move we’re surprised to see an OEM make. The 800 Dragon
RMK 163 comes standard with ice scratchers mounted to the slide rails. The
scratchers allow all of the running wheels in the rear suspension to be removed.
The front heat exchanger is also pulled off of this model. But remember—ice
scratchers only work if you use them.
Raw Freestyle Seat
The Raw chassis concept has been taken a step further with
the new freestyle seat. The new seat is 2.3 lbs. lighter and features a new
narrow shape for better rider movement. The seat has more in common with a
motocross bike seat than the traditional snowmobile seat.
Rev XP Chassis
Where to begin and where to end… The Rev XP chassis is
all-new from the ground up. Only the handlebar controls and skis were carried
over from the previous year. The XP chassis has several improvements over the
old Rev chassis. Mainly, it’s about 50 lbs. lighter (including other changes,
like the seat, suspension and handlebars). But beyond weight, the XP is
superior to the Rev in rider position, ergonomics and steering. The secondary
on the XP was relocated to a more upright position compared to the primary
clutch. This opened up the foot wells for an additional eight inches of foot
room. The XP features a 33-part steering system, which is 100 fewer parts than
the Rev’s. Every aspect of the chassis was designed to be lighter and more
rigid. Overall chassis weight is reduced by 11 percent, yet its rigidity
increased by 37 percent. The Rev XP chassis will be the catalyst of a
lightweight movement in the mountain sled segment.
The XP chassis’ over-the-tunnel-drive design places the
jackshaft above the carburetors rather than below them. The new drive system
features a two-roller on five-axis cam design. The clutch is designed to be
more efficient and backshift better than the old style, and it is also 2 lbs. lighter
than the old HPV roller secondary. Belt removal is a new concept, where part of
the clutch must be disassembled first. After the belt is reinstalled, the
deflection must be re-set—which is good from a tuner point of view, since each
belt is slightly different. But casual riders may find the belt changing
process a bit tedious. Cam changes are also
simplified with the new clutch.
Ski-Doo has gone the longest with a dated gauge design. So
it was only fitting to release a new digital/analog gauge with the XP chassis.
The basic digital/analog gauge (which comes on Summit Everest models) features
two dials—tach and speedo—and a small center digital readout for the odometer,
hourmeter and fuel. The gauge features warning lights for high beam, reverse
engaged, low oil, engine temp, low fuel, battery and DESS system. The premium
digital/analog gauge (found on X-package Summits) features a much larger center
three-zone digital display that is capable of digital readouts of rpm, speed,
altitude (upper zone), air temp, compass, fuel consumption (SDI only—middle
zone), odometer, trip meters, hour meter and clock (lower zone). The premium
gauge can also show peak speed, peak rpm, average speed and average fuel
consumption (SDI). It can also record data for up to 10 minutes and be played
back. It’s definitely a premium gauge.
It’s just another factor in the XP movement, but the
new hydroformed driveshaft is worth noting. As seen in other models,
hydroformed shafts are incredibly light compared to standard hexagonal drive
shafts. It looks big, but it is a hollow ribbed tube. But another factor of the
hyroformed drive shaft design is that the drivers cannot spin on the shaft—a
rare but hear-of problem with hexagonal shafts on high-horsepower applications.