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Table of Contents
Background and Overview
Reasons for Change
P2 in Action
All Clean Snowmobiles links
Only Operations links

Essential Links:

How Two-Stroke Engines Work
Explains how two-stroke engines operate and their advantages and disadvantages.

Clean Snowmobiles: Operations
Cleaner Snowmobile Technology Operations

Snowmobiles operate in cold weather. Cold, stable atmospheric conditions combined with unfavorable topographical features like mountain valleys can "trap" snowmobile pollution, causing high atmospheric concentrations of snowmobile pollution in areas with high snowmobile usage.

Traditional snowmobiles:

  • Utilize a two-stroke engine.
  • Are tuned to run "rich" (with excess fuel), resulting in incomplete combustion and the emission of carbon monoxide and unburned hydrocarbons.
  • Have not been required to and do not utilize any exhaust after treatment (such as catalysts) to reduce emissions.

Two stroke engines:

  • Feature a high power to weight ratio and good cold-start characteristics. However, they are inherently "dirty" engines.
  • Up to 1/3 of the fuel and oil can be emitted, unburned, from a two-stroke snowmobile engine due to "short-circuiting" of the fuel-air mixture.
  • Combustion of traditional two-stroke oils results in visible particulate pollution

Most snowmobile tour operators replace their snowmobile rental fleet annually.

Technical papers from the Society of Automotive Engineers' (SAE) have long been a source for keeping current with advancements in vehicle technology of all forms. SAE publishes about 2,000 papers each year which can be purchased online for a minimal fee (http://www.sae.org/servlets/ techtrack?PROD_TYP=PAPER).


Hub Last Updated: 08/08/2003

The P2Rx Topic Hub Project was developed by:
The Clean Snowmobiles Topic Hub was developed by:
Peaks to Prairies
Peaks to Prairies
Contact Laura Estes (Peaks)
406-994-3451 or laurae@montana.edu