I have a 5 hp Tecumseh engine on my craftsman snowblower is using premium gas in it a good thing or a bad thing for it

Its neither good or bad for it... as long as the gas is fresh (never store it off season with fuel in it)... the higher grades only cost more since the engine is not a high compression design that requires higher octane.

Hi,
You will get little out of the higher grades other than they have twice the stabilizer added at the refinery. That still does not allow it to keep for extended periods.
Peace,
Clarke

I agree, don't waste your money on premium. Your manual tells you what octane to use, right?