We’ve been paying attention to comments from SNOWTRAX viewers and SUPERTRAX readers for about ten years now about the reasons they wouldn’t consider a 4-stroke over a 2-stroke sled.

It pretty much always comes down to the same thing. The belief is that 4-strokes are just too heavy. A very common comment is this: “I’d buy a 4-stroke the day they build one as light as a 2-stroke!”

This is actually a very revealing comment. What snowmobilers are really saying is they love the reliability, torquey power delivery, longevity and low maintenance costs of a 4-stroke but are hung up on one single thing: Weight!

Although it seems like an insurmountable barrier to break through, we have an uncanny confidence in snowmobile engineering teams’ abilities to solve problems like this one.

Here are a few possibilities we’ve been researching:

EXOTIC MATERIALS:

Exotic doesn’t necessarily mean overly expensive. Chemists have been experimenting with sophisticated plastic composite materials that resist heat absorption – and when combined with nickel-aluminum or steel cylinder liners in a snowmobile engine – can end up being very light and still durable. Magnesium is another possibility here – even an alloy of titanium.

TECH:

There are already prototypes of a very lightweight digital cylinder head being tested that will eliminate the need for conventional valve gear and heavy camshafts and bearings as we currently know them. Instead, a system of solenoids activates fuel flow into the cylinders and efficiently controls combustion electronically.

FEWER CYLINDERS:

Although we love the sound and smoothness of three and four cylinder 4-strokes, big-inch twins have less parts and can deliver a lot of grunt. The idea of increased torque at lower RPMs instead of spinning engines at 10,000-plus revs has something to say about heat generation, too, especially when you’re considering using different materials than steel or aluminum in an engine.

MONOBLOCK DESIGNS:

One of the most popular and durable snowmobile engines of all time, Polaris’s Xtra-Lite triple used a one piece cylinder casting with little space between its cylinders. Most 4-strokes use this configuration today, but there are still weight-saving possibilities that could be applied here.

FRONT END WEIGHT REDUCTION:

Remove more front-end weight from the snowmobile itself, not just from the engine. The most common gripe with 4-stroke sleds is that they “feel” heavy over the skis. Perhaps by repositioning parts on the front half of the sled so the weight balance is more centered could alleviate this phenom.

This actually brings up another interesting discussion: What if a manufacturer designed a purpose-built 4-stroke snowmobile from the ground up – instead of the current trend to simply adapt a 4-stroke engine to a sled originally designed to house a 2-stroke?

Food for thought.

Strangely, most snowmobilers who ride trails these days seem to consider a 137-inch track a complete necessity.

It wasn’t long ago the first sleds out the showroom doors were the 120 and 121-inch length models that could pivot on a dime and run whooped-up sections of trail with the skis lightened just by moving your body position a few inches on the seat.

Arctic Cat was first to universally offer a longer 129-incher on its trail models and was eventually followed by every other OEM. This track length offered the best alternative – decent deep snow capability along with almost undetectably compromised turning.

Today, many trail riders deem even a 137-incher is too short to meet their needs. Thus, the newest breed of Crossovers are all equipped with 144 to 146-inch tracks. Has something happened to the trails? Is no one grooming anymore; so everyone has to be ready to ride in powder? Of course not!

What has happened is a giant marketing trend toward convincing the consumer they need to look like a mountain rider.

Back when a 121 was the hot ticket, the buyer image was of a snocross-style or cross-country rider who leapt huge spans of air or ran ungroomed ditches at incredible velocities. This image has worn through considerably the last few years and now average riders see themselves as back-pack wearing, shovel-toting vertical experts – even if they live two thousand miles away from any mountain, let alone one with snow on it. Most don’t even own a back-pack or a shovel.

I know those comments sound pretty harsh – but snowmobile enthusiasm is a constantly evolving phenomenon and it really shows how important it is that potential buyers see themselves a certain way. Does this mean we’re all just a bunch of lemmings hypnotized to do exactly what the OEMs bid us to do?

Honestly, I don’t think so. I think the image has evolved into long tracks mostly because of economics. With the high price of sleds due to the high level of technology they have today – snowmobile consumers simply demand more range from what their sled can potentially offer. Even if a pure trail rider buys a 137 or a 146-inch track and rarely or never goes off-trail with it, at least the potential is there if they ever need to.

Also, viewing things from an economic perspective, whenever it comes time to sell a long tracked sled a few years down the road, the used-sled appeal of a long track will reach far more potential buyers.

Don’t get me wrong – I’m not saying that all trail riders who buy long-tracked sleds are fooling themselves, trying to fit some kind of subliminal image the marketing departments have foisted on them. I personally know a number of long track owners who ride trails and also are very good powder riders, loving nothing more than to take their sleds into the abyss and at least, flatland and foothill ride in the deepest snow they can find. I think those numbers are actually growing.

The other side is, the OEMs have done a fantastic job with the ride and handling of longer sleds. Frankly, we’ve been very pleased to discover how well even a 146 can turn and steer on hardpack compared to a shorter tracked version. Uncoupled suspensions have been tuned and calibrated to the level they perform very close to what a short track can offer.

The simple fact is: There just isn’t much you have to give up by going long.

This is a question we’ve been asking around Supertrax headquarters for a couple of years now.

It’s interesting how turbos have become a staple of the snowmobile industry for about a decade – and their use on 4-strokes has become expected and accepted by the market in a big way.

Sleds like the original Arctic Cat 660 Turbo, late 2000’s Z1 Arctic Cat Turbo, Yamaha SideWinder, Polaris IQ Turbo and the Ski-Doo 900 ACE Turbo have been around a while and there’s no doubt the market is fascinated by the kind of power and torque you can get from sleds of this ilk.

Strangely, in the big picture, reliability hasn’t been much of a problem.

Ski-Doo has opened up new avenues of thought by actually going into the turbocharger manufacturing business and producing its own line of turbochargers for the PWC and ATV biz as well as for the 900 ACE snowmobile engine.

Frankly, this kind of investment can only mean one thing: There will be more Ski-Doo turbos coming in the future.

One harbinger of what’s to come is the application of a turbo to the 850 E-TEC 2-stroke in the Summit late last year. It’s the first of its kind and poses some interesting possibilities.

What possibilities? How about the introduction of medium displacement 2-strokes that can make the same power as big-inch 2-strokes. How about turbocharged 500cc 2-strokes that produce 160 ponies? There would be significant fuel savings at play and even with a beefed up bottom end and increased weight from a turbocharger and its plumbing, these sleds could still be light.

The torque upgrade from using a turbo on a small engine would make it feel very similar to a big-inch cousin at trail speeds. Maybe the extra torque generated from a small displacement turbo-2-stroke would actually exceed that generated by an 850.

It’s inevitable that fuel costs will continue to rise over the next ten years and the EPA will be focusing on the low hanging fruit of the recreational vehicle industry to “save the world” just like it did from MY2000 to 2010.

Thus, the automobile industry has relied on turbocharging to power small displacement 4-cylinder engines in lieu of V8 and even V6 powerplants.

What makes us think the snowmobile industry is exempt?

There is one caveat the engineers will need to deal with. Apparently, turbocharged 2-strokes do not currently meet EPA standards for certification and Ski-Doo has had to use EPA credits to get its turbocharged Summits into showrooms.

This could mean a trail-based 2-stroke turbo MX-Z would need to use a catalytic converter in order to be clean enough to certify.

That’s only a possibility if the creative minds at Ski-Doo don’t come up with another idea – and I wouldn’t bet against them!

We’ve selected four 10-year-old sleds we think would be good choices to look for as used sled buys this winter. We’ve deliberately chosen sleds with longer tracks to more accurately reflect the type of riding enthusiasts are doing in this decade.

One advantage is we’ve been able to make our selections based on the track records of both performance and reliability these sleds have exhibited down through the last ten seasons. Take a look and let us know what you think!

2011 SKI-DOO RENEGADE 600 OR 800 137

MARK SEZ:

These second generation REV Renegades were really good, lightweight snowmobiles with impressive power-to-weight ratios with either a 600 or 800 Rotax E-TEC underhood and the 137-inch rMotion skid delivered an incomparable ride at that time. Handling was okay, but not world shaking.

Overall it would be hard to find a better used ride provided you locate a low mileage copy. Here’s what I mean specifically. The Series III 800cc, cylinder reed Rotax was a sweet runner with E-TEC induction. Everything remained good with this engine until the 10,000 klick or 6000 mile threshold was reached.

Once past this mileage tally the PTO (clutch) end of the crankshaft had a habit of spitting its bearings out of the cases. If you must go over the 10K/6M threshold then confine your search to the Series III 600 E-TEC or an 800 that has had a rebuild. The 600 has a much better rep at that age than the 800.

The use of a 16-wide track has mostly disappeared from today’s X-over market, however, the 16 x 136 Camo-sneaker used on this vintage of Renegade was highly effective. These Renegades could easily pop on top of six fresh inches on Kevlar Lake and deliver a ton of sno-mobility.

Keep in mind Ski-Doo has been number one in the biz for more than fifteen years. This means there should be a good supply of these desirable sleds for you to choose from when shopping for a 10-year-old ride.

KENT SEZ:

I fully agree with Mark’s choice of the Renegade. These were great crossover sleds because they were so light and had the benefit of a 16-inch-wide track. Their shorter 137-inch length still had incredible floatation and really good off-trail handling because of the 137 track width compared to the competition using 141 and 144-inch tracks. Both the 600 and 800 E-TECs were strong running, reliable engines in both powder and on groomed trails.

There are lots of Rennies and 15×120-inch MX-Zs from this era still on the snow and you should have a good selection of used ones to choose from. Like Mark says, try to find one with less than 10,000 K on the odometer, if possible.