Two-stroke engines aren't dead. Well, they might be in cars, but they're more alive than ever in snowmobiles. Forget the smoke-spewing, spark-plug-fouling, expletive-inducing engines of the past.

Darker days may be on the horizon for combustion engines, but before they're forced into retirement, they're going out with—ahem­—a bang. In this golden era of combustion, there are many engines that ...