I inherited a rototiller when we bought our current house a few years ago. I'm not a gardener and I'd like to sell this on craigslist. I can get it to start by spraying starter fluid into the carburetor, but it sputters out once the starter fluid is consumed. I'm guessing that whatever gas in the tank is "bad" and the carburetor is gummed up. I know that there are more than a few options for fuel additives to remediate bad fuel and/or remove varnish from the carburetor and needle valve. Do any of you have any specific products that you can recommend?