Giving us their insights and the benefit of their snowmobile experience, our evaluators spent some serious saddle time with the best of the best mountain snowmobiles for 2014: The Ski-Doo XM Summit X 154, Arctic Cat ProClimb M8000 Sno Pro Limited 153 and Polaris 800 Pro-RMK 155.

Though these three mountain snowmobiles are much the same as the 2013 offerings, they are snappier and more refined. We understood this early on for the M8000, where Arctic Cat made some excellent refinements in rear suspension placement, gearing, clutching, EFI calibration, and weight loss, but for the XM Summit and Pro-RMK – where did their “overhauled” performance come from?

Mountain snowmobile evaluations are not statistically stable from one day or weekend to the next. Snow conditions change, temperatures and humidity fluctuate and a driver’s mood flips up and down with each passing mountain.

2014 Mountain SnowmobilesThe three mountain maulers and two crossovers were tested to the best of our abilities. Pictured here, and with grins, are L-R, Greg Huntsman, Eric Mathews, Kevin Allred, and Jerry Mathews.

The data recorded in Part I of our comparison may have validated or invalidated what you know or knew about your XM Summit, Pro-RMK, and M8000. For you crossover folk, the number crunching may have secured your decision to purchase a Yamaha RS Viper XTX SE or Polaris Switchback Assault with RMK track. Both are good products.

Read Part 1 of our 2014 Mountain Snowmobile Shootout

Before we move on to driver input, we must trump the blessings of a well-prepared snowmobile. Bott Yamaha/Ski-Doo, Idaho Falls, ID, prepped our XM Summit X; it was the dealership’s sled. In conversing with dealer owner Bob Bott, we asked him what his shop did to make the stock XM Summit run so well. He summarized by stating, “Clutching for elevation.” It clicked. Bott dialed the XM’s clutches for altitude. “Not many dealers send out their snowmobiles for elevation, but we do.”

Listen up dealers; send your customers’ new snowmobile out the door with the correct clutch springs, helixes and weights for the rider’s given altitude. It worked for us in our shootout and will surely work for your dealership.

Who gets to be an evaluator? Here is a little info on our test riders:

Greg Huntsman, Idaho Falls, ID. Occupation: Software Sales Years Snowmobiling: 34 Why Snowmobiling: Enjoyable recreation activity. How Many Snowmobiles Owned: Three Favorite Riding Style: Mountain boondocking. Standing with feet on both sides (straddling the seat), mountain climbing and weaving through trees.

Jerry Mathews, Rigby, ID Occupation: Operations Manager, Starting Line Products, Inc. Idaho Falls, ID Why Snowmobiling: I absolutely love the sport. I was born into a family that loved anything with a motor and that love has never left. There is nothing like swinging a leg over a snowmobile and squeezing the throttle on a bright fresh snow day. It’s therapy for the soul. How Many Snowmobiles Owned: I’ve ridden every significant performance snowmobile since 1998 and owned many. Years Snowmobiling: 29 Favorite Riding Style: Backcountry boondocking in deep snow

Eric Mathews, Idaho Falls, ID Occupation: Sales at Starting Line Products Why Snowmobiling: I was exposed to the motorsports industry at a young age and have always had a passion to ride these machines in the great outdoors. How Many Snowmobiles Owned: I have worked for SLP for the past fifteen years and have ridden every significant model in the last six. I’ve personally owned four. Years Snowmobiling: 18 years. Favorite Snowmobile Owned: 2002 Polaris 700 RMK. Favorite Riding Style: Boondocking through trees.

Arctic Cat ProClimb M8000 Sno Pro LE 153

2014 Arctic Cat ProClimb M8000 JumpSeasoned Guest Test rider, Jerry Mathews pitches the Arctic Cat M8000 up over a tuft, which the M8000 can do quite well with its best-of-the-best track. The M8000 has the engine power and track to dominate. Its ski is its weak point.

Greg Huntsman

The 2014 M8000 is a great improvement over last year’s in terms of maneuverability. The M8000 has a very stable suspension and a very responsive motor. I did notice snow did not stick to the painted tunnel and rails. The M8000 is a great looking sled.

My complaint for the M8000 is that it’s not as comfortable on the bumps as the Ski-Doo XM Summit.

Jerry Mathews

I love the track on the M8000. The 2.6-inch PowerClaw this sled uses is my favorite stock track. It provides a good balance between powder and packed snow performance. The 2.6-inch lug provides great penetration and propulsion as seen in the drag race times (it was consistently fastest). Where it lacks is top speed, but this is a specialized mountain sled and I’ll take that trade-off.

This sled lacks a bit in the ski department. When you have an aggressive track, it takes an aggressive ski to break it loose in a turn. The stock Cat ski tends to “push” more than the other two sleds and it doesn’t offer much flotation either. I didn’t feel as fast or as comfortable in the timed and gated hillclimb course because of this (partly due to the aggressive track as well I’m sure).

Read our review of the 2014 Arctic Cat M8000 Sno Pro and Limited

The engine is a powerhouse that has proven to be extremely durable and well accepting to mods. This day it was responsive as always, turning the track with ease. The clutching is better this year from the factory. The sled held its RPM well with changes in elevation and snow conditions. It was running about 8100 rpm at wide-open throttle. Arctic Cat definitely should get credit here for a job well done (many changes to the clutches happened in 2014).

The sled felt lighter and more nimble than its predecessor. And the benefit to the limited cooling system is it does not allow snow and ice to buildup on the tunnel and running boards. However, the negative to the limited cooling system is we had to run the ice scratchers down as soon as we hit the trail to keep the engine cool.

The new suspension mounting felt good, but the shock pressure had been increased to reduce ski lift and I felt the rear shock was a little stiff for the trail bumps we encountered getting to the mountain. The rear suspension rear mount location was in the upper holes and I think I’d prefer to have it in the lower holes with the shock pressure lower.

The seat is light; there really isn’t much to it. It is not as comfortable as the Polaris RMK and Ski-Doo Summit, and it is a little on the short side (does not run far enough toward the rear of the sled) and I found the back of it a couple of times. I’ll accept this short seat for the weight savings it offers. I like the additional storage in it.

Eric Mathews

The suspension on the M8000 worked well in deeper snow, but it was set a little stiff for the deep moguls we encountered on the trail. On the trail it did seem to dart around more on the way in than the Ski-Doo Summit did on the way to the mountains.  (Note: The stiff suspension is’s doing. We pumped up the rear suspension Fox Floats to 150 P.S.I.)

The M8000 was a bit harder for me to bring up on an edge, some of this is from my lighter weight and some is from the skis that aren’t quite as aggressive as the Ski-Doo or Polaris in loose snow conditions.

On the hillcross course once it was rutted up, it took more effort to keep the M8000 between the gates and I was often taking corners wider than I had with the Ski-Doo or Polaris.

Steering effort was slightly more than the Ski-Doo, but not as much as the Polaris. The M8000 did seem to push the most in the turns out of the three 800s.

Polaris Pro RMK 800 155

2014 Polaris 800 Pro-RMK JumpAs Pros go, the 2014 Polaris RMK Pro is the best yet. Here Eric Mathews finds flight with the Pro 155. Polaris has built a mountain snowmobile that is forgiving, predictable and easy to ride. Yet, among all these, it remains aggressive, attacking hills like a bounty hunter with hunger pains.

Greg Huntsman

Responsive motor. Easiest of all to sidehill and maneuver in all terrain. Forty pounds lighter than the other two sleds in the same category.

Its suspension is stiff in the bumps. Snow sticks to the tunnel and back of the rear suspension rails.

Jerry Mathews

The Polaris 800 Pro RMK is at home boondocking through tight trees. It is comfortable on its side pulling wicked side hill maneuvers we didn’t think were possible a few years ago. It is lightweight, agile and predictable. The best part about a Pro is it requires minimal effort to ride. This lets you ride longer with more energy. The 2014 Pro models seem to be better calibrated and more efficient than previous models.

The ski on the Pro is the best OEM ski. It provides fairly good flotation, but I still find it pushing in the corners a bit. I was comfortable on the Pro on the timed and gated hillclimb course, but I did not feel it was as fast as the Assault. I feel this was a combination of the narrower ski stance (width) and the longer track that make this sled more at home in the deep snow and technical riding rather than on a gated hillclimb course.

Read our review of the 2014 Polaris 800 Pro-RMK

The seat on the Pro is comfortable to ride. It is pretty short (lengthwise), but I didn’t find myself sliding off the back. Its cushion is wide enough to provide a stable seated platform. Being short has its positives as you have less to swing your leg around when hopping back and forth from side to side.

The suspension worked nice all the way from the whopped out mountain trail to the deep snow.

Ultimately at the end of the day the Pro was a fun and capable sled to ride. There is not much negative you can say about it because it really does work well.

Eric Mathews

The 2014 RMK 800 ran very well. The steering was slightly more aggressive than the Ski-Doo or Arctic Cat, which made riding in the powder a breeze. Once the hillcross course was rutted up, the skis would grab and throw me around a bit more than the Ski-Doo.

The chassis is forgiving and I could comfortably sidehill wrong foot forward. It did take a bit more effort to roll the sled up on its side than the Summit.

Steering effort on the 800 RMK was the highest of the three 800s, but only by a small margin. Out of the three 800s the Polaris pushed through the corners the least.

Ski-Doo XM Summit X 154

2014 Ski-Doo XM Summit X JumpThe 2014 Ski-Doo XM Summit X 154 was prepped by Bott Yamaha/Ski-Doo, Idaho Falls, ID. It is much improved for 2014.

Greg Huntsman

Smooth suspension that eats up the bumps on the trails.  Responsive motor. Easy to sidehill and maneuver on terrain with varying slopes. Very comfortable seat and riding ergos.

Complaints? None, except it still weighs 40 pounds more than the Polaris…. but it doesn’t feel heavier when in the saddle.

Jerry Mathews

I was a surprised how well the Ski-Doo XM Summit X 800 worked. I was not expecting it to be much different than the 2013, but the 2014 is much refined. Clutching was spot on, and the sled performed well in all conditions we exposed it. It has the typical XM trait, allowing it to easily initiate a sidehill maneuver and hold it there. In the snow conditions we were in, it didn’t “wheelie” when hitting a short vertical wall in a climb like the 2013.

The XM chassis is easy to move around on. When aggressively running the timed and gated course, I felt comfortable jumping from side-to-side, railing the corners and throwing it around. I fouled up on my first run as I missed my line and got out of the groove making for a slow time. I think this was mostly due to having just got off the Polaris and where these two sleds have very different steering (Polaris has a vertical steering post while Ski-Doo’s is laid down over the motor) – it takes some getting used to. My second run felt fast and comfortable.

Read our review of the 2014 Ski-Doo Summit X

I like the Ski-Doo suspension both on the whooped out trail as well as in the mountains. It was calibrated well and made for a comfortable ride. The seat is also very comfortable to ride on. It is about the right length and didn’t get in my way when I was boondocking or railing around the timed course.

The handwarmers on the Ski-Doo are awesome. If you really need some heat to dry your gloves out, this is the sled.

Overall, I give the Ski-Doo very high marks for the snow depth and conditions we had that day.

Eric Mathews

The 2014 XM was dialed in. It was responsive and it transferred its horsepower to the ground. In a drag race on a groomed trail, I was able to jump ahead and walk away from the other 800s. I was the lightest rider in the group (165 lbs before gear).

Steering effort is very minimal. I would say the XM is the easiest for the three 800s. It did tend to push more than the Polaris in turns.

The XM chassis was easy to get around on and made for easy sidehilling. It didn’t take much effort to roll it up on its side.

Jumping from the Arctic Cat or Polaris to the XM was a bit of a shock and it did take some time to get used to the geometry of the sled before I was comfortable enough to aggressively ride the sled.

I liked the plush ride of the XM best out of the three 800’s.

Polaris Powder SledsWaiting. Sometimes, as the day wears on and hunger strikes, snowmobilers will take a breather from chasing gates, timing lights and cornices.

The Results

Greg Huntsman
Categories Summit X M8000 Pro-RMK
Rider’s cockpit 5 5 5
Track performance 5 5 5
Deep powder performance 5 5 5
Motor performance 5 5 5
Drivetrain performance 5 5 5
Runningboards 5 5 5
Skis 4 4 4
Overall Average (Points Total Divided by 7) 4.85 4.85 4.85
Jerry Mathews
Categories Summit X M8000 Pro-RMK
Rider’s cockpit 4 4 4
Track performance 4 4 4
Deep powder performance 4 5 4
Motor performance 4 4 3
Drivetrain performance 4 4 4
Runningboards 4 4 4
Skis 3 2 4
Overall Average (Points Total Divided by 7) 3.85 3.85 3.85
Eric Mathews
Categories Summit X M8000 Pro-RMK
Rider’s cockpit 5 5 5
Track performance 4 5 3
Deep powder performance 5 5 4
Motor performance 5 5 5
Drivetrain performance 5 4 5
Runningboards 5 3 5
Skis 4 2 5
Overall Average (Points Total Divided by 7) 4.71 4.14 4.57
Combined Overall Scores
  Summit X M8000 Pro-RMK
Greg Huntsman 4.85 4.85 4.85
Jerry Matthews 3.85 3.85 3.85
Eric Matthews 4.71 4.14 4.57
Overall Average 4.47 4.28 4.42

The Conclusions: 800 Class

There it is, the XM Summit X busted out on top of the mountain with an overall score of 4.47 with the RMK Pro .05 of a point behind. The M8000, though it posted many high marks, fell into third place; unfortunately its downfall was its ski.

2014 Arctic Cat M8000 CarvingEric Mathews lays a hard left in front of mountain Sentries, old growth trees near Alpine, WY. The M8000 is a carving fool, but its ski often makes carving harder than it should be.

We agree with our test crew. The M8000 is’s most improved mountain sled for 2014, but its ski, like a small pebble in a giant’s shoe, brought the mighty M down. But, look at the M8000’s motor and track performance – stellar. One may read ski hit and not care, skis are swap-out items in the West where aggressive aftermarket skis are added; drivers always take motor and track performance far and above ski performance. We agree with this too. So, drop the ski and the M8000 would have been the gold medal recipient; it was 0.19 of a point behind first and 0.14 of a point behind second.

Read our 2013 Mountain Snowmobile Shootout

Let’s look at it this way, like our stats and data in Part I, the point spread is, well, hair-splitting. Any given weekend, any given day, any given driver, this could and would change.

The RMK Pro remains a steady performer – predictable, steady, faithful and responsible. The 2014 Pro is that sled where a rider can depend on its deep-powder performance, weekend in and weekend out.

We give you data that flushes out a 1, 2, and 3. But with many years experience, we ask you to be wise, as the OEMs have delivered mountain snowmobiles that are so close, so near perfect, that all three, in our humble opinion, are wickedly close.

The Crossover Experiment

Test driver, Kevin Allred said it best, “We threw the RS Viper XTX SE into the harshest conditions.” Which we did. Jerry Mathews said, “The wide front end provided lots of stability, the shorter track was easy to toss around and the chassis was nimble and forgiving.”

Read our review of the 2014 Yamaha SR Viper XTX SE

2014 Yamaha Viper XTX SE JumpThe Yamaha RS Viper XTX SE, though short on track lug height, was pulled completely out of its element and told to climb high or go bye. Yamaha has a good future with Viper XTX.

For the Yamaha RS Viper XTX, Huntsman said it had a comfortable suspension and seat, and its motor is responsive. Jerry Mathews added, “We happened to have a Viper available to us, so we took it with us as well. It was the sled to have on the trail headed to and from the mountain as well as the whooped out mountain trails. Once we got to the deep snow at elevation, its lack of track lug height and length showed, but it was not really designed to be a deep snow mountain sled. If you keep it in its element, the Viper is a wonderful sled to ride.” Eric Mathews picks this up by stating, “The Viper was a bit underpowered and under tracked for the conditions we were riding, but it did make it everywhere the mountain sled went eventually.”

Jerry Mathews went deeper, “I think it [Viper] is more of a 70/30 sled spending 70% of its time on trails, but able to take on the challenge of some powder when the opportunity arises.  It is capable of some off trail riding, but the track holds it back somewhat because the Cobra track does not quite have enough lug height to allow it to run competitively with the Switchback Assault (the Switchback Assault had a 2-inch track) in deep snow conditions. However, on the trail it is extremely fun and comfortable to ride. It is confident in the corners, takes the bumps well and is easy to ride.”

Read our review of the 2014 Polaris Switchback Assault

We agree with this statement from Jerry Mathews, “The Switchback Assault is more geared for the Powder as it was outfitted with a deeper lug track than the Viper. I [we] felt for a 50/50 sled, it worked extremely well. You do have to carry more momentum with it than the RMK in deep snow and you have to work a bit harder to sidehill it, but it is really a good option for a customer who rides the trail as much as the deeper snow and is not planning on riding aggressively in super technical terrain.”

2014 Polaris Switchback Assault JumpThe Polaris Switchback Assault is a favorite. With its optional RMK Series 4.0 powder track, it can go steep-n-deep. Multi-year guest test driver, Greg Huntsman throws a roost.

The two crossovers were subjected to difficult situations, yet they handled themselves quite well. To compare them against the 800s is unjust. We’ll just add that the Assault and Viper XTX handled the harsh conditions with no fear.