4-Stroke 1200 Under 500 pounds! Last year Ski-Doo shocked the world with their MX Z TNT that weighed 399 pounds! The sled wasn’t a...

4-Stroke 1200 Under 500 pounds!

Last year Ski-Doo shocked the world with their MX Z TNT that weighed 399 pounds! The sled wasn’t a fan-cooled cheater, it was a liquid-cooled 500SS (actually a big-block 600) that propelled the lightweight sled with authority, and provided Ski-Doo riders with an unfair power to weight advantage that hadn’t been seen in years.
2008 also marked the introduction of the REV-XP platform. Back in 2003 when Ski-Doo came out with their truly revolutionary REV that introduced the world to rider-forward seating, it was an adaptation to their existing chassis technology and underlying mechanical layout. When the REV and rider forward was validated, they knew what the next step was; to redesign the entire snowmobile around rider-forward, not just adapt it to their status quo.

This brought us the REV-XP platform, with its repositioned drive system that provided the extra eight inches of leg room, and gave us a snowmobile that got rid of extra weight and mass. These things are snowmobiles, which means we use them in the snow, and that requires flotation. Snow is not pavement, even if groomed trails are kind of packed down like pavement. We do use them in a deep medium and require them to be maneuverable and at times, we have to manually pull them out of a snow bank.

Rumor was there were some different looking REV-XPs running around northern Quebec last year, slightly bigger looking and more muscular. Our suspicious mind led us to believe that maybe they were going to not let the dust settle on their mighty 1000 SDI two-stroke that only saw duty for a short time. Or, could there be yet another attempt at making a viable four-stroke?

Ski-Doo had been watching Yamaha’s market share creep up ever since their stunning introduction of the RX-1 back in 2003, at the same time as the REV intro. Four-stroke sleds amounted to 27% of the market for 2008. This is expected to grow to 36% for 2009. Were they just going to sit back and watch? Research data indicated that while the western and midwestern riders were waiting for the E-TEC two-strokes, the riders in the east, and especially their backyard of Quebec, had a hankering for the durability of the four-strokes. Nobody can deny the long term durability characteristics of the four-strokes. Even as clean as the new E-TEC is and it’s non-existent oil smell with fuel economy that is actually better than most four-strokes, some riders simply wanted the torque and performance of a four-stroke that would last for thousands of miles, much like their car.

But Ski-Doo kept coming back to that weight thing. These are snowmobiles, not cars. We ride them through the snow, not on paved roads. They are performance vehicles, not merely transportation modes. Can’t we make a four-stroke lighter? Can’t we make one under 500 pounds? Sure they could, and they did.

Enter the 2009 MX Z TNT 1200 with a weight specification of 499 pounds. No typo there; four-nine-nine. That’s about 25 pounds less (on paper at least) than the Yamaha FX Nytro.

Fitted into a new version of the REV-XP chassis called the REV-XR, this new platform was designed to be more muscular looking and be able to handle the added size and torque of this new, built-for-snowmobiling 1200 4-TEC Rotax engine. The XR version is slightly bigger, but cosmetically very similar with improved wind protection as well. Many of the parts are actually interchangeable with XP sleds. Most of the difference is in the body panels and engine bay. The suspensions are pretty much the same, front and rear.

So the big news here is truly the all new 1200 4-TEC. While Ski-Doo made a couple of 4-stroke sleds up to this point, this is the first “performance” 4-stroke they’ve made specifically for a snowmobile. And what a gem.
This is a different animal. It is aimed at the meat of the market 130 HP class, not the high-end hyper sled class of the 800s or the 1000s, so don’t let the 1200cc fool you. The displacement is for broad torque, not all-out horsepower. This isn’t a high-revving engine, it is more of a grunter. For it’s class, you can expect the best torque, widest powerband, a lower operating RPM to make its peak power and torque, and a sound that is truly unique and unlike any of the other four-strokes. Combined with the REV-XP platform, it provides the best handling four-stroke to date, as well as the lightest one. We won’t go as far as to call it the best riding one; we’ll reserve that for the GTX SE/LE or the Arctic Cat Z1s.

Torque you say? Ah yes, that magical thing that spins the crankshaft and lifts the skis when you give it the gas. Can you handle 100 foot-pounds? At 6500 RPM? Are your eyes big yet? They should be. How about bandwidth? It makes 125 HP all the way from 7500 RPM on up, and gives you 130 HP from 8000 RPM all the way to 9500 RPM+. This engine is a stump puller with broad, wide, massive sweetness from a four-stroke.

The sound of the 1200 is different between the MX Z versions and the GTX models, through different manifolds and such. We’re told Ski-Doo worked closely with Rotax in Austria to give it a refined performance sound. The target was more of a European sport car than a sport bike. It sounds like it is somewhere between the higher frequencies of super bikes and the lower rumble of V-twins or musclecars. It’s kind of throaty and you won’t be calling it “industrial”.

Of course, being a 4-TEC it delivers excellent fuel economy and is super clean (cleaner than the Yamaha Vector and Nytro engines, according to Ski-Doo). We’ve seen fuel economy right at 18 mpg, consistently, but it all depends on how and where you ride. Not quite as good as the E-TEC, which has been a couple clicks better and usually more like 20-21 mpg in like conditions. Both of these can be down around 15 mpg if you’re really pushing them and have some fresh snow that increases the drag, so it is all relative.

OK, back to the engine. This is an in-line three-cylinder that makes 130 HP at 7,750 RPM. It has a big 91mm bore and a short 60mm stroke for lower piston speeds. Electronic fuel injection is dead-nuts on the money from what we can tell. Dual overhead cams run four valves per cylinder. It boasts chain-driven cams with finger-followers that Ski-Doo engineers were quite proud of. They tell us it is like what the BMW 804 engine uses and is a first in the snowmobile world. The benefit is greatly reduced mass in the drivetrain with much less engine noise. Dry sump lubrication lets it start easier in the cold. A single counter balancer keeps it smooth; not as smooth as a FX Nytro or Apex, but still quite smooth.     Service requirements are simply an oil and filter change every 3,000 km (roughly 2,000 miles) or once per season, with a valve adjustment every 20,000 km (12,500 miles).
Riding the MX Z TNT 1200 you might question the 499 weight figure, as the engine does place more of a bias on the skis than a two-stroke. Just like the Yamahas that show a light weight on the scale, a four-stroke carries more weight up front so they feel different. An Arctic Cat F8 that actually weighs more on the scale feels lighter on the snow. But you can’t deny the fact that this is the better handling four-stroke, and you know it is a REV-XP based machine. Take your MX Z from last year and refine the suspensions and give it a four-stroke with 100 foot-pounds of massive power and you get the idea. The engine doesn’t spin as quickly as the FX Nytro and doesn’t snap to attention as quickly, but the powerband is noticeably wider. It wails on the Arctic Cat Jaguar engine, as it should, but isn’t a match for the Z1 Turbo. The Polaris Turbo isn’t even in the same league.
So if you still like flickable lightweight two-strokes, you will notice the added mass of the 1200. If you want a REV-XP (XR) that gives you quiet and clean operation for thousands and thousands of miles, like 10,000 of them, then you need to consider the hefty price tag of the 1200. This isn’t for casual riders as much as it is for serious high-milers. The more you ride, the more you will appreciate it. In the TNT you get the performance-based suspensions so you can still go bashing the moguls, as an MX Z should. It’s right where you could paint it red and call it a GSX, but we’re OK with it being yellow and called an MX Z. You will be as impressed as we were.

The 2009 Ski-Doo MX Z TNT 1200 retails for $10,549.

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