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The 4-stroke mountain difference
The difference between a 2-stroke and 4-stroke powered machine is significant and as the Yamaha is the only 4-stroke mountain machine it’s a bit of an oddball compared to everything else in the mountain class. We always struggle with which class to put the Nytro in when it comes to our comparison articles, as it doesn’t really compare to any of the 2-stroke classes. Based on horsepower it falls into the 700 category, but the 700 category doesn’t really exist any longer, so it’s basically a powerful 600 with a bit of a weight disadvantage.
We happily ran Yamaha’s flagship mountain machine, the Nytro MTX SE 162 in our test fleet this past winter. This is the highest spec mountain Nytro available with an upgraded suspension and a longer track than the standard MTX. It’s much improved from the previous Nytro, the weight savings definitely helping, but probably an even bigger improvement came from the tipped-up tunnel, different approach angle of the track and narrower running boards. These changes allow the machine to get up on the snow better, making the Nytro less likely to trench and get hung up on its running boards.
Yamaha has become known for its reliability and build quality and while the fit and finish is not quite as polished on the Nytro as the Vector and Apex, it’s still very good. We never had any concerns about the Nytro breaking down and leaving us stranded either. The belt life is fantastic, it doesn’t require any oil and its electric start is still very much a luxury in the mountain segment. And when other sleds need to be towed back to the trailer the torquey Nytro is always the machine picked to do the pulling.
Nytro’s biggest handicap is that it just doesn’t have the power to weight ratio of the other leading mountain machines. Obviously there are only two ways to improve this, one is to boost the power and the other is to make it lighter.
Unfortunately we think Nytro is probably about as light as it’s ever going to be. The sled is pretty lean and there really isn’t much unnecessary weight anywhere, and there are quite a few exotic materials used like the aluminum chassis and magnesium chain case. The SE’s suspension is pretty light with air shocks and all the excess weight has been trimmed out of the rear skid making the machine’s rear surprisingly light. Even compared with the 2-stroke 800s, Nytro seems the lightest to lift by its rear bumper.
Yet even though the Nytro has a nice torquey powerband it’s still a bit underpowered for its weight. Yamaha rates the 1050cc triple at 130 hp, but we know this is slightly on the conservative side, our independent dyno testing on similar Nytro’s has shown that they usually produce closer to 140 hp. If Yamaha engineers could squeeze 150+ hp from this engine they would really have something, or even better, build it at the factory with either a supercharger or turbo.
Ever since the RX-1 came out we have been dreaming of a factory boosted Yamaha, but it just never happens. Yamaha does offer a supercharged Waverunner watercraft, so surely if a family of three can be trusted to blast across a lake with no helmet, us mountain snowmobilers can be trusted with a 200-horse snowmobile to access the backcountry.
In the mountains last season the Nytro performed pretty well as long as the snow wasn’t too deep or too hard. In either of the extreme low- or high-snow conditions Nytro’s weight becomes a hindrance. But in a foot of powder the sled handles well and will get around fine.
Nytro’s handling is pretty good and in our powder evaluation it surprised everyone by finishing our hillcross course in second place against lighter, more powerful 800s. More extreme mountain riders would struggle with a stock Nytro, but with an aftermarket turbo or supercharger this machine would be in a class of its own when it comes to high-marking.
While not for everyone Nytro fills a niche in the mountain market that is not being addressed by others. It’s a decent performing machine with legendary Yamaha build quality and reliability, plus it doesn’t burn oil and has great belt life.