well, it is possible that 9 year old gas is better then the stuff they are selling at the pump these days. Really!

The sniff test would be the starting point, it either still smells like gas, or it doesn't. If it smells like varnish, get rid of it. If it smalls like gas, I would be tempted to get a little out of the tank (not much) and put it onto a cement driveway, away from everything, and throw a lit match into it and see if it would burn. If it burns, I might be tempted to use it. If it doesn't burn, it all goes away. Drain the tank, blow out the fuel lines, and empty the carb and blow out the passages. Start with fresh gas.

If you are unsure after reading all the comments here, drain the tank, blow out the fuel lines, empty the carb & blow out all the passages. Its probably not worth taking the chance it still might be OK.