Snowmobiles go 4-stroke for quiet, smokefree riding-at speeds up to 137 mph.

PLYMOUTH, Minn. (AP) — Polaris Industries on Tuesday introduced a new four-stroke snowmobile engine that is cleaner and quieter than the traditional two-stroke engine.

While the quieter, cleaner 4-strokes have grown in popularity, many Mainers still are faithful to their lighter 2-stroke snowmobiles.

Four-stroke engines continue to gain relevance in the past couple of decades. Yamaha, for example, now produces only four-stroke engines in their snowmobiles. In the past, snowmobiles had as little as ...

The noise production of the four-stroke snowmobile was 68 dBA during an independent wide open throttle acceleration test. If the fourstroke snowmobile were to replace all current, two-stroke ...

ROSEAU, Minn. — David Johnson liked to say laziness inspired the first Polaris snowmobile. An avid outdoorsman, Johnson said he built the first snowmobile in January 1956 as a way to enjoy th… ...