November 2, 2007

Hungry For The Good Stuff



Serving up a helping 700s

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 thereof.

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 done.

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 700cc Liberty 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 Line-Up

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 with.

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.

Powder Prowess

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 good.”

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 dissect.

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 up.

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 snowmobile purchase.








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