In the September issue of SnoWest we dished out some tasty tidbits of information for you to
chew on concerning the up and coming Polaris 700 RMK IQ and Yamaha FX Nytro MTX—hopefully
just enough to get your mouth watering for the gory details of the ingredients
in the “shake and bake” of this sumptuous duo.
With our testing session being up in the thin air (we sat at
well over 12,000 feet above sea level more than once) of the Colorado Rockies,
some of us were exposed to a couple extra challenges last spring. First was the
extreme conditions we encountered and second was the oxygen p.p.m.—or lack
With some resourcefulness we were able to find some nice
spring powder for two days of great testing. But the oxygen issues just
wouldn’t go away, taxing man and machine alike, which included a penalty of a 3
percent power loss for each 1000 feet we gained in elevation above sea level.
No matter, for we thrive on challenges and did get our job
So, as radio talk show guru Paul Harvey says on his Saturday
program: “And now, for the rest of the story.”
700s No—140s Yo
We’ve always grouped the sleds by close-to-like cubic centimeter
displacement classifications in the past, but may have to change to horsepower
classifications as a result of 4-stroke technology. This class is a perfect
example of the need for this change when it comes to in class comparisons.
The Polaris RMK in this class is powered by a liquid cooled
twin cylinder, two-stroke with the Cleanfire Injection-4 fuel delivery system. This
motor’s performance is controlled by a Digital CDI with Throttle Position
Sensor (TPS), Water Temperature Sensor (WTS), Detonation Sensor (DET) and Variable
Exhaust System (VES). This little twin has been dynoed at an impressive 140
(the new magical number for class comparisons) hp, which is 15 percent more at
peak than the previous 800cc VES motor, creating enthusiastic SnowTester feedback.
One SnowTester said, “The best power package of 2007 is still going to be one
of the best for 2008.” Another said, “Really like the bottom end—very
responsive, great throttle response.” More comments included, “Excellent power—can
compete with some of the 800s.”
The 140 horses are delivered to the track via the legendary
combination of the Polaris P-85 drive clutch and the Light Weight Team (LWT)
driven clutch. Stopping power is provided by the Phantom hydraulic disc brake.
The power for the Yamaha FX Nytro MTX is provided by a
liquid cooled 1050cc Genesis three cylinder with 4 valves per cylinder fed by
41 mm Mikuni fuel injection throttle bodies. This pumped up, fast revving, high
torque (94 ft/lbs) Genesis has amazing low end grunt and never ending top end
pull thanks to its 138 peak horsepower out put. The Yamaha 4-stroke has been
test proven for incredible durability and ecologically minded economy with no
lubricating oil consumption or smoke and reduced fuel consumption.
Other attributes of the 130 FI engine are the electric
start, a more linear powerband for a less “peaky performance” and the new
Engine Braking Reduction System (EBRS), delivering a much smoother off throttle
deceleration. Post testing comments included, “Great torque—pulls hard,” “Good
throttle response for a 4-stroke,” “I like the EBRS a lot” and “Good power but
could use a bit more for its weight.” The Genesis 4-stroke go-go is transferred
through the Yamaha heavy duty clutch system and whoa is accomplished with a 4
piston hydraulic brake with a lightweight disc.
Lookin’ At The
Yamaha introduces its brand new FX Nytro MTX in two
variations for 2008. There is the standard model with the Team Yamaha blue and white
colors and the anniversary edition sporting a red, white and black special
scheme commemorating Yamaha’s 40th year in the biz.
The FX Nitro MTX replaces last year’s Vector Mtn. SE at 90 fewer
pounds (553 lbs. dry, 544 lbs. with no reverse) and a 14 hp increase. Needless
to say, there is a no comparison between these two machines.
The new, lighter weight FX Nytro chassis is true by a
modular design with a 4 piece tunnel, comprising an 8 piece chassis with a
rugged chromoly tube front construction. The compact design puts the engine
down low and way back, centralizing the mass for dramatically improved agility
and a sportier rider forward positioning. Another plus is the all new third
generation front A-arm suspension with 40 mm aluminum HPG shocks, link-type
sway bar and adjustable ski stance. This new package delivers 8.5 inches of
improved ride comfort and adjustability along with superior anti-bottoming plus
flatter handling and cornering.
The only down side to this combination we found was the
saddleless mountain ski, which was over aggressive and a “bit unnerving in
crusty or hard pack conditions” as one test rider described the prototypes.
The final component complementing the FX Nitro MTX
chassis/suspension package is the ProMountain 153 rear suspension. This rear
skid was debuted in ’05 and continues to perform as engineered with some subtitle
improvements such as a more shallow approach angle on the rails. The
ProMountain is a conventional torsion spring design, delivering good weight
transfer and 11.5 inches of vertical travel using gas cell shocks in tandem.
The dual angle rails give the FX Nytro MTX less push on the trail or hard pack
while maintaining its deep snow flotation.
The general consensus amongst the test crew was, “The
overall chassis balance is a little nose heavy,” which is a common trait of the
heavier 4-stroke motors in the big moguls. But one SnowTester said, “the FX
Nytro MTX eats up the smaller moguls” and “Chatter bump ride is glass smooth,”
and “small bumps—this Yamaha soaks them right up.”
For 2008 Polaris enters its second year with the RMK 700 IQ. Last year, this 700 in the Dragon trim,
single handedly saved the Polaris deep snow performance segment. This year, you
have three variations of the RMK 700 to choose from. There is the standard RMK
155, the Dragon RMK 155 and the Dragon RMK 163.
When we test these machines, we like to focus on the special
packages such as the Dragon—not because they are usually Snow Check purchases
or have cool paint and/or graphics that photograph well. We like them because
we ride hard and feel the need for the upgraded suspension packages that come
The Raw RMK chassis debuted in ’07 and proved to be what
Polaris needed. A purpose built sled that is lightweight and ideally balanced
whereas control is a premium quality. For 2008 the Raw RMKs are 5 lbs. lighter
than last year, further enhancing their performance, without sacrificing
durability. Some post testing comments include, “Very well balanced with all
aspects of stability and handling being very good,” “This 700 inspires
confidence in the rider—I really enjoyed riding it” and “Best in class all
around (stability and handling).”
The IQ RMK front suspension is a viable factor in these
characteristics. It has an adjustable ski stance for the Gripper Skis that we
like in all conditions and 9 inches of travel through a pair of plush
performing Walker Evans Air Shocks. New for ’08 is a redesigned ski spindle
that has reduced steering effort by 15 percent and has lessened the suspensions
unsprung weight by one pound.
Rounding out this awesome set up is the RMK rear suspension
with the functional dual angle rails which Polaris brought to the industry
years ago. This skid has great weight transfer and 15.5 inches of travel for
the 155 inch track and 16.5 for the 163 inch track.
Once again the premium ride is provided by a Walker Evans
Air Shock in the front and a Walker Evans HPG-1PF shock in the rear. That
resulted in SnowTester comments like, “Very good in the big moguls along with
being smooth and stable in the smaller bumps” and “One of the best traits about
the machine is its handling—really doesn’t matter the conditions, stutter
bumps, big moguls and hard cornering.” New for 2008 are rear idler wheels and
axle that result in a 1.25-pound savings.
The 2008 FX Nytro MTX comes with no track options just as
the 700 Dragon did in its rookie year. Yamaha’s track of choice for the FX
Nytro MTX would be the Camoplast Maverick 153. The Maverick track has been on
the market since 2006 and has proven to offer amazing traction and flotation in
most snow conditions found in the mountains as well as nimble handling in
technical maneuvering situations. This track measures 15x153x2.25 and features
a 3-inch pitch, unique lug design and a guide clip on every third bar to keep
performance up yet reduce rotating mass.
The FX Nytro MTX uses extrovert drive sprockets to keep the
Maverick hooked up while completely eliminating any ratcheting associated with
the longer mountain tracks and good horsepower. Yamaha opted to go with a 15-inch
wide track instead of the 16, keeping the FX Nytro MTX as narrow as possible
for good sidehilling qualities and the 153 inch length to keep away from that
“station wagon look and pushy feel.” There were some mixed emotions with this. “The
deep powder sidehilling was good but the chassis needs a more radical trapper
for more running board clearance” and “The Maverick has good traction and all
around performance, but Yamaha needs to consider a longer option, especially
with the dual angle rails,” SnowTesters wrote.
Year two brings us the RMK 700 in three variations, the
standard RMK 155, weighing 489 lbs. dry, the Dragon 155 at a weight of 484 lbs.
dry and the Dragon 163, tipping the scales at 489 lbs. dry.
Both the 155 and 163 tracks are of the latest and greatest
Series 5.1 design with a 2.4-inch tall paddle. When compared to the previous
Series 5.0 track, the new 5.1 has an optimized lug pattern producing 19 percent
more forward lug contact with the snow. Not only that, the 163 track weighs
less for an ideal balance between ultimate flotation and nimble handling.
Polaris has added an extrovert center driver on the 163 to eliminate ratcheting
and only works under a load so there is no friction during normal operation.
Testers said, “Both tracks have lots of flotation and good traction for
multiple conditions” and “Sidehilling characteristics and flotation are very
All Dressed Up (And Some Place To Go)
Top of the line rider ergonomics and creature comforts are a
must to complete the experience of extreme mountain riding. Both the Polaris
and Yamaha have mostly good and a little not so good in this department. Let’s
Windshields that really offer some protection are nearly a
thing of the past. The FX Nytro MTX has the low-pro look providing zero
protection, whereas the bubble shield and little wings on the RMK do offer some
protection from the elements.
Both machines come with reverse as a standard feature, a
feature we are really are big advocates of.
Gauges and instrumentation on both units are good with their
control button and knob locations. Both also have a Digital Multi-Function
Display with plenty of information and warning lights. The Polaris has the
larger MFD that is located closer back and the Yammies’ is smaller and located
farther out, making it a little harder to read.
Now for the three most critical aspects of rider
accommodations—our feet, seat and hands. Let us start at the bottom and work
The FX Nytro MTX has running boards that run the full length
of the tunnel and are plenty wide enough to hold the biggest of club feet.
These wide boards do have some flex in them, but are most likely not a concern.
Boot traction was rated “good” by all the test riders along with the snow
diffusion except in sticky conditions.
The RMK has shorter (two thirds length) boards that are also
narrower than the other manufacturers and there is a reason for that: sidehilling
characteristics. So even though the room is limited, the boot traction was
thought to be “very good” by most, helping to keep big feet on board. Like the
Yamaha, snow diffusion is good except in sticky conditions.
The snowmobile seat has gone through some major changes in
recent years (along with the handlebars) in order to accommodate the western
riding style requires a lot of standing for increased leverage.
Our evaluation scoring is based upon firmness, grip, width
and height, the latter being the most important in relation to the handlebars
and easy sit/stand transition.
The FX Nytro MTX seat scored “good and excellent” in all
categories with the test crew, as the RMK Freestyle seat received “just right”
and “great” reviews the whole way through.
Based on our scoring system and tester feedback, the
connection between the seat and handlebars on these two ponies are what we
like. Some comments about the Yamaha include, “Very nice set up—easy sit to
stand transition,” “Good width and height—like the molded in hooks with good
grips and being heated clear to the end” and “Good height and width—my favorite
handlebar and grip.”
Keep in mind, the Yamaha is decked out with a fully
functional mountain strap and 10-position hand/thumb warmers.
We found the angle of the bars or steering post to be a
little odd in certain situations of sidehilling, but other than that, fell in
love with the package.
The Polaris handlebar is also popular with the crew as width,
grip/hook combo and height were all rated “good” across the board. “Personally
for me, the handlebar setup is just right,” one SnowTester wrote. We did have
one 6-plus footer who was whining for the 2-inch taller riser like the 800. The
RMK also has a mountain bar and adjustable hand/thumb warmers, similar to the
FX Nytro MTX.
Apples And Oranges
After reading about the rest of the story, you are probably
ready for us to pick the “140” Class winner.
This is where the word “evasive” comes into play as we plead
no contest. For other than horsepower numbers, the FX Nytro MTX and RMK Dragon
don’t have a lot in common. There are two different motor technologies here
with dramatically different powerbands, not to mention the 60-plus pound
difference between the two.
Kinda like comparing honey dew melon to cantaloupe or beef
to chicken or apples to oranges. Depending on your tastes, or not, we are
excited with what the Polaris RMK/Dragon and Yamaha FX Nytro MTX have to offer
and firmly believe both are deserving of a serious consideration for a new