The old adage stating an internal combustion engine is nothing more than an air pump can be graphically illustrated in two new Rotax engines powering Ski-Doo snowmobiles.

The new 600R E-TEC engine arrived two seasons ago as a completely new design producing 125-HP. When we received word of the new 600R and had to sign embargos keeping it a secret, we were surprised Ski-Doo didn’t write chapter two of its “How to One Up the Competition” novel.

What do we mean? The writing was clearly on the wall after Ski-Doo introduced the 850 and smashed the 800-class mold. Why didn’t they drill bigger holes and make the 600R a 650R? Obviously, the rest of the story is history.

BACK TO OUR POINT

The new 600R E-TEC engine employs every trick in the Rotax 2-stroke book to deliver a pleasing surge of EPA compliant thrust. The engine is a pleasure to squeeze on tight trails or big pulls up Kevlar Lake.

A new, lighter and rationalized E-TEC injector is used along with new E-RAVE exhaust port modifiers. The engine’s durability and anti-wear properties are improved with an exotic cylinder coating process that sprays the aluminum cylinders with a super hard and durable liquefied metal that’s finished by an equally exotic polishing regimen.

The 600R, while closely mirroring the 850, does not have a 2-piece forged crank. Rather, it uses a conventional, pressed together “built” crankshaft. The new 600R idles smoother, delivers low-end power more efficiently and transitions to shift RPM virtually seamlessly when compared to the Series III 600 E-TEC it replaced.

The engine has been a hit since its intro. Keep in mind, the 600 class is still the most prolific engine size in the biz.

INHALE

Remember what we said about an internal combustion engine being an air pump? That is undeniably true and proven by the way the newest 600 using EFI facilitates the 600R E-TEC platform by simply altering its ability to inhale and exhale – more commonly stated as its ability to “suck and blow”.

Clearly, the 600 EFI engine is built on the same cases, crank and cylinder castings. The big change comes with the substitution of the complex and costly E-TEC direct injection fuel delivery system.

This includes the substitution of E-TEC’s complex, 50-amp electrical system and engine control module (ECM) with a more garden variety, low pressure, throttle body EFI fuel system.

E-TEC injects fuel directly into the combustion chamber from the cylinder head mounted injector after the rising piston closes the exhaust port. The 600 Sport EFI introduces fuel into the throttle body located outside the combustion chamber and scavenges that fuel under the piston, up the transfer ports and into the combustion chamber.

On the exhaust side of these two engines the exhale differences come into play. The 600R E-TEC uses ECM controlled servos to activate the RAVE port modifying “guillotines” in response to a jillion inputs into a highly complex 3-dimensional ECM map.

Essentially E-RAVEs compliment E-TEC’s precision injection of fuel and assist the direct injection system by holding unburned gasses in the combustion chamber. As the E-RAVEs move up and out of the exhaust port, the engine is able to pump more air for increased high RPM power.

EXHALE

On the exhaust side of the 600 Sport EFI engine there’s no exhaust valves – period. The 600 EFI engine relies on a tuned expansion chamber to hold up unburned exhaust gasses using reverse pulse waves resonating back to the fully unrestricted exhaust port.

However, it must be noted both the volume of incoming fuel and air and the volume of spent exhaust gasses leaving the 600 EFI are dramatically reduced when compared to the 600R E-TEC. This is why the 600 Sport EFI delivers 85-hp and the 600R E-TEC produces 125-hp.

I know what you’re thinking – would the 600 EFI produce more power by bolting on 600R cylinders? Let me say this – don’t even think about it! Switching cylinders would require a complete re-mapping of the Sport’s EFI ECM. It Is doubtful the new EFI system could deliver the volume of fuel needed to make a Frankenstein version of the 600 Sport.

SDI, DSI, EFI

The idea of EFI for 2-stroke use is not new. Arctic Cat’s Suzuki 800 twin used a very effective throttle body EFI system for many years to produce heroic power. Just to be clear – EFI isn’t SDI.

Semi-direct injection introduces fuel to incoming air in the transfer or boost port on the cylinder. SDI is currently in use on Arctic Cat’s new 800 twin and Polaris Liberty and Patriot engines including the all-new 650.

Dual Stage Injection (DSI) is used by Arctic Cat on its potent 600 twin. DSI injects fuel on the top of the piston at relatively low RPM and then transitions to injecting fuel both on top and under the piston with the same injector as RPM rises.

That’s all we can tell you about the new 85-hp Ski-Doo 600 Sport engine, for now. One question we are poised to answer is whether or not an aftermarket expansion chamber could increase the 600 Sport’s output. Stay tuned.

Now that the dust has settled and everyone has had a look at the 2021 Yamaha line-up, we’re wondering where the intro of a line of 2-strokes is going to go with Yamaha down the road.

We’re not so focused on the new Venom (400cc 2-stroke single) line as much as we are on the SDI 800 2-stroke Yamaha is using in the Mountain Max and the Transporter.

BTW: In our opinion, the Transporter 800 is so close to being a Crossover sled – given the fact the industry is going with longer and deeper tracks on sleds like the RIOT, Assault and Backcountry, that the Transporter logo could easily morph into a crossover-adventure hybrid without having to use too much imagination. Certainly, its upgrade in power adds a ton of appeal for Yamaha buyers who want to spend more time off-trail than on.

Getting into the mountain market with a high-tech, lightweight 2-stroke sled makes the Mountain Max super-appealing to two types of buyers: First, the most obvious is the Yamaha guy who has wanted to be an altitude rider the last couple years. The Mountain Max will fill the bill nicely.

The second type is the rider who can’t get an Arctic Cat because he-she didn’t lay down the fresh to get in on an early-season purchase. True, this isn’t a problem now, but in-season, when the Cat offer expires on early-orders, the only Cat-like mountain sled you’ll be able to see in showrooms will be the Mountain Max, provided the Yamaha dealer early ordered some of them for inventory. We think a lot of purebred Cat artists will be shopping for an M-Max then.

Another point is Yamaha’s pricing. So far, the published premium on a Mountain Max is about $600.00 more than the Alpha One. Frankly, this is a bit troubling but if you give it some consideration, you need to remember that Cat is offering killer prices on all of its sleds if you slap down a deposit early.

Since there are no in-season, in showroom Cat sleds available and if Yamaha holds its price to where its intro puts it, the Mountain Max’s price tag may turn out to be pretty reasonable later in the season.

As far as value goes, customers who step up for the Mountain Max 800 will not be disappointed. This is a truly fine snowmobile, well-researched and with some real props against what Polaris and Ski-Doo are offering.

We think this is a toe-test of other Yamaha 800 2-strokes down the road – perhaps a lineup of 146-inch 800 X-TX models or even 137-inch L-TXs or 146 Ventures.

Looks like, if you’re “in for a penny, you’re in for a pound” with the door now opened wide for more 2-stroke Yamahas. We love it!

I’m pretty sure something important just happened in the sno-mo-biz and a bunch of people – media included – completely missed it! What happened you ask? The race to produce the “Spark” snowmobile just heated up – and did it in a pretty big way.

WHAT IS A SPARK?

Spark is the model designation for Sea-Doo’s most popular PWC ever. In fact the largest selling product BRP manufactures is the Spark PWC. It sells huge because when it came to the market three seasons ago, BRP offered it at the mind-boggling MSRP of $4,995.00 USD.

BRP CEO Jose Boisjolis’ genius was to take the popularity of riding and owning a PWC back to the level it crested at in the late 1990s. His call was to bring a fully capable, fun and unapologetically, real PWC to the market and thereby re-energize the PWC biz. By the way, it worked.

IS THERE A SPARK SNOWMOBILE?

Yes, we believe there are three to choose from and the Spark paradigm is rapidly becoming a legitimate segment. Admittedly, we are never going to see a Spark snowmobile with an MSRP of $4,995.00 US. Why? Because snowmobiles are far more costly to manufacture than PWCs.

Snowmobiles have wheels, brakes, transmissions, shocks, suspension systems, lighting systems and tracks. PWCs are essentially two injection-molded pieces of plastic powered by a 4-stroke engine connected to a sump pump.

WHAT’S THE RIGHT PRICE?

I’m not 100-percent sure what the right price is but I am positive what the right sled is. The Spark goal line will be reached when a value sled is fully capable of running with full-on snowmobiles in the 600 segment.

Before Ski-Doo introduced the Sport 600 a few weeks back, there was Polaris’ first-in (two seasons ago) Indy EVO 550 fan and earlier this winter Arctic Cat landed the ZR BLAST 400 EFI. Most recently Yamaha unveiled its version of the BLAST, coined the SX Venom.

Here’s what the MSRPs look like for the Sport and the BLAST in the US and Canada:

BLAST (65-hp 2-Stroke Single)
USA – $7,695
CDN – $10,095

MXZ SPORT (85 HP 600CC 2-Stroke Twin)
USA – $8,649
CDN – $9,999

REALITY CHECK

I won’t comment on these numbers other than to say, go and check out the new Ski-Doo Sport MX-Z. At $8,649.00 USD and $9,999.00 CDN there is a ton of value – and just as importantly – a ton of performance offered for this kind of jing.

I can tell you from firsthand experience the new Sport MX-Z with an EFI 600 Rotax twin under its hood producing 85-hp delivers a genuinely legitimate snowmobile experience. Don’t think about 4-stroke power – think about lightweight 2-stroke power. Think about advanced G4 chassis, bodywork and ergonomics. Think about a full size snowmobile a guy can ride and not be left in the snow dust by his buds. Think about a brand new, warrantied 600cc snowmobile for the price highlighted above.

DID YOU FEEL THE EARTH MOVE?

It’s entirely possible the market leader, using its enormous economies of scale, has actually delivered the Spark snowmobile. When Spring Break orders are counted, the Sport 600 MX-Z may be an eye opener.

We can’t help but think the decade from 2000 to 2010 brought about the greatest changes in the snowmobile industry and was the most revolutionary time span in snowmobiling’s history. This series explores some of the most revolutionary advancements this sport has ever seen…

CROSSOVER EVOLUTION

Let’s say it this way: As we move further into the future the average snowmobiler wants his or her snowmobile to do more than just one thing.

The roots of this mindset go back to the early part of the Golden Decade. Ski-Doo introduced the ZX-based Renegade in MY 2000. Soon, all the OEMs began upping track lengths and delivering sleds with 133, 137 and even 141-inch tracks.

Back in the day crossovers were pretty bland rides with usually nothing more than a 137-inch track with (sometimes) a slightly deeper lug. Most buyers believed these longer track variants couldn’t handle as well as their trail-based 121s.

Later in the decade, the definitive crossover snowmobile continued to develop and change. Mountain handlebars, bar risers, altered ski-stances, deeper lugs and specialized skis for better flotation began to appear.

As snowmobiles continued to change during this period the emergence of the purpose-built, zero compromise mountain specific snowmobile became cemented in the product profile of every OEM.

Today, the definitive crossover is still very much in flux – so much so that in MY 2020 most OEMs offer two (or more) different executions of the genre. There are now trail biased Crossovers and off- trail biased variants.

Like it or not, the crossover genre was born in the Golden Decade. Necessity is the mother of invention and the crossover personifies this credo.

Remember this: As it was in the Golden Decade, so it is today. Snowmobilers want their sleds to do more than just one thing!

We can’t help but think the decade from 2000 to 2010 brought about the greatest changes in the snowmobile industry and was the most revolutionary time span in snowmobiling’s history. This series explores some of the most revolutionary advancements this sport has ever seen…

THE POLARIS RUSH

The RUSH, with its Pro-Ride external shock back end, gets its own category for the Golden Age because it, like the original REV, established a benchmark in the industry.

In late 2009, the RUSH concept shifted the paradigm that had long-since established a snowmobile should be built a certain way, with a shock or two inside the skid. Up to this point, it had looked like there was just no other way to build a snowmobile.

The Pro-Ride external shock rear suspension twisted everyone’s sensibilities upon its arrival. The concept boldly claimed the set-up was virtually impossible to bottom and delivered true rising rate movement.

As it turns out, a rising rate response to bumps is not always the best response unless you’re a certified ditch banger. Nonetheless, the Pro-Ride suspension and the RUSH’s unique, indestructible cast aluminum bulkhead assembled – using of all things – glue, and over-arching mid-chassis design brought the focus back to Polaris in the Golden Decade.

Polaris proved you could be successful with a non-conventional chassis and yet still deliver the goods snowmobilers want.