Remove the gas cap and inspect it for debris. The small vent holes should be clear to prevent overheating.
Turn off the engine and check to make sure nothing is clogging the bottom of the unit where the snow enters. A large stick or rock can cause the unit to seize and overwork itself.
Check the fuel mixture in your unit. Make sure you are using the correct ratio of fuel to oil for your unit. Most Toro Powerlite units require a 16:1, 32:1 or 50:1 gas to oil ratio.
Make sure your choke is in the "Run" or "Fast" position to prevent overheating.
Inspect the mounting brackets on the engine. Tighten the brackets with a wrench if they are loose.
Remove the cover to the carburetor and remove the filter. Clean it with carburetor cleaner to remove any debris.