1993 Middleweight Specials Comparison

The contenders.Right now, among the sport’s most hardcore enthusiasts, no class of sleds is more popular than the middleweight performance special class. It is the class of snowmobiles that has garnered most of the attention by most sledders, will likely have the greatest parity on both the track and trail, and will be the topic of the greatest number of banterings amongst pitstop pundits. There’s one simple reason why — because the middleweight specials are the most accessible and attractive class of snowmobiles to the greatest number of trail riders. It’s the class that speaks to most of us.

A step down from the raw and awe-inspiring power associated with the musclesleds, but a step up from the trail performance class that once ruled the sales roost, performance specials seem to bridge the gap that snowmobilers wanted to cross. The current crop of performance specials combine the power that was once available only with the musclesleds just a few short years ago and the trail manners of the trail performance machines.

Introductions are in order: from Arctic Cat we have the new EXT 580 Z, Polaris offers the now-in-full-production Indy XLT Special, SkiDoo chimes in with their new Formula Plus ER and Yamaha presents the new Exciter II SX. Each of these snowmobiles has the right stuff. The question is, which one has the most of it?

Apologies: Qualifying the Results

Our testing and evaluations of each of the sleds took place last March in West Yellowstone, Montana, at the Snow Goer/Snowmobile Magazine Rode Reports. The sleds that we rode were either prototype or pre-production models and, with the exception of the Exciter II SX, received updated changes after we tested them.

According to Arctic Cat, the EXT 580 Z we tested wasn’t quite up to snuff in the power department — no thanks to the fact that it had the wrong exhaust pipe (the correct pipe hadn’t yet been finalized for production). Arctic claims the correct pipe will make significantly more power. Additionally, the production Z will have floating piston Fox gas shocks instead of the remote reservoir units we tested.

1993 Arctic Cat EXT 580 Z
Similarly, Polaris changed their Fox emulsion ski shocks to internal floating piston units after the Rode Reports. The rest of Polaris’ changes came at the rear of the sled. Instead of the Yokahama track that was on our test sled, all new Indy XLT Specials will have a Camoplast track that supposedly works better in chewed up snow. Mother major change from our test sled to actual production XLT Specials was the rear Fox gas shock, which has since seen several valving updates.

Ski-Doo, whose all-new EFI Formula Plus engine still had a few bugs at the time of our Rode Reports, has since corrected the glitches that occasionally plagued our rides. Even more important, they didn’t have the Formula Plus X at the Rode Reports, which would otherwise have been the sled included in this test.

Typical of the Yamaha camp when it comes to Rode Reports, their fleet of sleds, including the Exciter II SX, was set and ready for production.

With that in mind, it’s impossible for us to say exactly how the production units will face off against each other. Our evaluations and opinions are just that — our opinions. The Snow Goer test crew leans towards aggressive riding, and our tests were performed at 8,000 feet above sea level at unseasonably high temperatures around 45 degrees F. Different conditions would likely affect our opinions.

Enough said — on with the comparison.

1993 Polaris Indy XLT Special
Suspensions: First Impressions are Critical

For most of the people who buy performance specials, trail riding constitutes the vast majority of the time they ride. The same is true for the Snow Goer crew, which is why we place so much emphasis on a sled’s suspension. Whether it’s nasty moguls or smooth trails you’re riding, the front suspension sets the stage for the rest of the sled’s handling. It makes the first impressions.

The best front suspension of the four sleds belongs to the Indy XLT Special and its 6.25” of travel. No other front suspension offered the same combination of comfort and control over different terrain. Slamming through the bumps, no other front end stays so predictable. Indys have long had a handling advantage that starts with the dual radius rod, trailing arm design called IFS. Said one test rider, “With the Fox shocks you get fade-free performance all day long. You simply can’t fault this front end. It’s the best in the business.”

1993 Ski-Doo Formula Plus EFI
Second place honors go to the EXT 580 Z with its wishbone design, Fox shock dampened AWS front. Steadily improving with time, the AWS isn’t as plush all the way through its 7” of travel as the IFS. With valving updates from the master Cat racer, Kirk Hibbert, the 580 Z’s front end works best when you’re riding aggressively. On smooth trails, however, the AWS front turns quicker than the Indy, and offers less roll. This year the AWS was tuned the best we’ve ever ridden (due in large part to the updated valving). Until it works better in the bumps, however, it’s still second fiddle.

The preload-adjustable ThS front suspension on the new Exciter H SX is the best calibrated front end we’ve seen from Yamaha. It tackles the bumps using more of its 6” of travel than ever before. Even in the big holes, the TSS has improved steadily, probably due to a wider 38” ski stance. Unfortunately, the TSS still doesn’t handle stutter bump turns like its competition. The front stifi rolls during hard cornering, and the skis still get the “shakes” while cornering through ripple bumps. It seems that the TSS front has yet to utilize its full stroke the way other designs do. Until it does, third place is its home.

If all you did was ride smooth trails with a lot of turns, you’d want the PRS front suspension on the Formula Plus EFI. With its stiff preload, progressive rate and wide 39.75” ski stance, the Plus receives top honors in the cornering department. If the trail is smooth. Unfortunately, not all trails are, and when you hit the bumps, the Plus is too stiff. The fact that there is very little shock stroke for the 6” of travel results in a compromised calibration. Now, put the new DSA suspension found on the Mach Z and MX-Z on this sled…

Rear Suspensions: At theBack, Where You Feel it


Judging the four rear suspensions proved a more formidable task than we’d expected. There are two crucial tasks the rear suspension must perform — shifting weight and isolating the rider from the ride — that are accomplished in varying degrees by the four brands. Hours of riding through the late afternoon on West Yellowstone trails, where the closer you get to town the more the bumps begin to rattle your teeth, told us which suspension isolated riders from the bumps best. Constant stops/starts gave us an indication of which suspensions best transferred weight, and just plain old trail riding was used as a barometer for combining both.

The battle for top honors came down to the EXT Z’s Fastrack rear and the Exciter II SX’s Pro-Action Link rear. Aggressive riding over rough terrain found the Fastrack with the upper hand. With a claimed 8.5” of travel, dampened by Fox gas shocks, the EXT Z could handle long periods of bumps and holes better than the challengers. Said one Snow Goer test rider, “You have to ride the EXT Z hard, and when you do you’re rewarded with a far more comfortable ride than the other sleds. The Fastmk, with the Fox shocks, kept the track on the ground and me on the seat. It was the most comfortable in the bumps.”

The Pro-Action Link, when tested over the rough stuff, was too soft on compression dampening and thus would bottom out too easily. The nitrogen-charged Kayaba shocks performed well, but long rides over the stutter bumps produced noticeable fade. If the Pro-Action Link, with its claimed 7.7” of travel, was tuned for a more aggressive ride, with better shocks, it would take top honors. Since both suspensions transferred weight well, with a balanced shift, Arctic gets the nod by virtue of its “bumpmanship.”

The best weight transferring rear suspension belongs to Polaris and their new ITS (Improved Transfer Suspension, not ironically) rear. Gone are the progressive linkages, and the whole unit is mounted further forward on the tunnel. The result is a hang-onto-your-helmet transfer which, during both formal and informal drag races this winter, is sure to win a lot of soda money. Problem is, the ITS transfers weight too well. Every time you hit the gas coming out of a corner, the suspension would transfer so well it left the skis dangling. Not good.

The second problem we had with the ITS was its manners in the bumps. “Harsh,” was one comment heard after a test ride. The rider was referring to the fact that, even with the 7.75” of travel, it was still bottoming out too easily for our tastes (with Fox gas shocks, no less). That, along with the unnerving tendency of over- compensated weight transfer, firmly placed Polaris in third place, rear suspension category.

Ski-Doo, too, knows how to build a suspension that transfers weight extremely well. The engineers at Ski-Duo have played with the twin shock, progressive rate design for several years, and each year at the Rode Reports we feel the incremental improvements over previous years. h spite of its evolution, the SkiDoo rear is still the most uncomfortable suspension of the performance special class. What it makes up for in weight transfer, it loses the minute you come to a rough section of trail. The progressive rate design, coupled with 6” of travel with gas-charged Kayaba shocks, is too stiff in either holes or stutter bumps. One tester’s comment, after a particularly rough session: “I don’t care how soft the seat is, the Plus threatens to boot your butt into the next county every time you hit a deep hole.” Fourth place.

Motors: The Truth in Testing

Six years ago, each of the motors in this comparison would have been formidable motors found in musclesleds of the time. That tells you not only the power progression in snowmobiling, but just how strong these engines really are. For many patients of snowmobihiig, the 580 class engine is just what the doctor ordered. A whole lotta power, but not too much. Each motor in this comparison is a winner, but one is just a little more so.

That motor, is the 579cc liquid-cooled triple in the Indy XLT Special. Here is a motor with enough low-end grunt to pull stumps, enough mid-range to keep the skis light for a long way and enough top-end that good tuners will be hitting the century mark with regularity. The initials XLT refer to the motor, meaning Xtra Light Triple, which itself refers to the lightweight design of the engine. Polaris claims this motor weighs the same as the 488 EFI twin, only with a bunch more power. It was no surprise that each of the Snow Goer test riders ranked the XLT as top motor.

Running a strong second, the pumped up 580cc liquid-cooled twin in the EXT Z works best in the mid-range. At nonnal trail speeds, the EXT Z had the kind of power that always left us satisfied. Top speed was close to the XLT, but far enough back to determine a clear winner, and the bottom end was equally as steady. What the right pipe would do, we can only speculate.

Third place goes to the trigger-happy Exciter II SX. With reworked port timing and ingnition, and the new flatslide MikUni TM38 carburetors, the 569cc Exciter worked best in the low- and mid-range. In fact, the SX displayed perhaps the best low-end pop of the group. Top-end, the SX is a little flat, especially compared with the XLT and EXT Z. For trail riders who want great throttle response though, the SX is your sled.

Which brings us to the Plus EFI. We love the fact that the 580.7cc Rotax twin is now available with electronic fuel injection. The Mikuni-made injectors are a departure from the Bosch units both Arctic Cat and Polaris use, and hold true promise of near-perfection. There were still a few glitches with the system we tested, which Bombardier assures us are fully worked out. That said, the Plus has excellent low- and mid-range. The Rotax twin probably has as much torque as the XLT, which is what you likely want in a trail sled. Top-end speed was down compared to the XLT and EXT, but that might not be the fault of the motor. The Plus is a heavier sled than the other two, which takes its toll on acceleration and speed.

The Package: Adding up the Parts

We could spend hours debating the individual merits of one aspect of a snowmobile, only to do the same with the next part. In the end we’d have parts of the sum. That’s fine, but it doesn’t really tell us what the snow,nobile is like. Only when we look at the snowmobile as a whole, complete unit, can we make a judgment of its good and not-good qualities. It’s more general, but every bit as important.

The Formula Plus EFI was outclassed by the competition in this comparison, and no wonder. It wasn’t designed to be stuck with this competition, the Plus X was. On the other hand, the Plus EFI fared better in this crowd than expected. On the down side, the Plus EFI is heavy (from 15 to 50 lbs heavier than the other sleds). Additionally, the front and rear suspensions are too stiff, and leave little by way of comfort when the trails get bumps. We’re not talking moguls, but regular Saturday afternoon trail bumps. On the upside, the EFI-equipped Plus has just that — electronic fuel injection. As snowmobilers who like to spend less time wrenching in favor of more saddle time, this is a big plus. On smooth trails, the Plus ER rides like a sports car — on a rail and heading the direction you point it. The soft seat does wonders to soothe what would otherwise be very sore rumps. The Plus EFI is a good sled, but in the company of greatness, fourth place is the answer to the question.

1993 Yamaha Exciter II SX
The Exciter II SX is the best trail snowmobile Yamaha has ever built. No doubt about it, the SX carves, corners and coasts better than any Yamaha we know of. Like the Vmax-4, the wider 38” ski stance improves the Exciter’s manners in the rough. It still has the best seat foam of all the manufacturers, and the new, wider handlebars have the best shape of any sled going. The spirited motor has the best throttle response in the class, and the Pro-Action rear suspension is still the best design. Plastic bottom skis take the honors in that category, and probably hint of what we’ll see with the other brands soon. Of course, there are some problems.

The TSS front suspension, despite its most convenient preload adjuster, has yet to handle bumps the way we expect it to. The front “jitters,” as one tester put it, made for several complaints during the Rode Reports. Unfortunately, the best brake lever in the class activates some rather mediocre brakes. While Yamahas are notoriously great in the ergonomic department, they have yet to learn how to make proper foot stirrups — ones that are easy to lock into and hold the foot in a more level position. The gauges are good, but their position isn’t ideal. The windshield, while far less irritating on warm days than higher units, provides almost no protection. Add it all up, and the Exciter II finds itself in third place, with very few apologies.

Three years of fine tuning the AWS chassis have benefitted the original EXT “Special.” Both the front and rear suspensions are working better than they ever have, in all conditions. Add a strong motor, good ergonomics and great cornering and you’ve got all the factors lined up for a first rate package. Almost.

The EXT-Z did almost everything well, not always brilliantly, but respectably well. It had the best rear suspension, the second best motor, the second best front suspension, and the second best brakes. Sounds like a lot of second place votes, huh? We thought so too.

Additionally, the EXT-Z still harbors a few hang-ups. The biggest of which is the infamous Arctic “dart,” which is its tendency to wander on the trail when you’re trying to hold a single line. It’s not as bad as it used to be, and it’s possible to use the lower profile skis to mostly eliminate the situation, but the tradeoff is less-aggressive cornering, which isn’t in the cards for our purposes. The other problem, as we see it, is that the EXT lists for $100 more than the Indy XLT (but still less than either the Exciter II SX or the Formula Plus EFI). It’s a small, but significant, point we felt deserved mention in a competition this close.

Giving the EXT-Z second place was not an easy thing to do. In fact, the whole place picking process almost degenerated into a fistfight between the editors, it was that tough. After much teeth gnashing, we finally settled on the XLT Special as the class winner. At least there was no teeth bashing, and everyone is finally speaking to each other again.

So, why did the XLT win the comparison? Because it has the best motor in the class, the best front suspension, the best brakes and what most test riders agreed was the best looking overall combination.

The XLT’s 580cc lightweight triple kept the rest of the class in its sights on the low-end and through the mid-range, but it stomped them all on top. The XLT’s IFS front end worked just fine in normal riding conditions, but when the trails turned tough, it left the rest of its classmates for dead. The XLT’s liquid- cooled hydraulic brake provided consistently quick stops just like the others, but at the end of the day there was no fading and no adjusting to deal with, unlike some others. And finally, the XLT’s looks turned the heads of even the most jaded West Yellowstone snowmobilers. Us too.

Still, even the king of this class wasn’t without its shortcomings. The ITS rear suspension’s unnerving habit of unloading the front end in corners (when you hit the gas) left many testers leery about riding the XLT the way they had always ridden other Indys. The result is a modified behavior that leaves you rolling on the power rather than just grabbing a fist-full of throttle. Too bad, we had more fun the other way. We also had more fun in the bumps with other Indys, but the ITS doesn’t soak them up the way the old suspension used to. It’s a step backwards for Polaris, but the XLT Special wins anyway. SG


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