I bought a used mower the other day, a Honda HR214. It is well used and needs a good cleaning. When I found the offer on craigslist, it said it would start on the first pull. When I showed up to pikc it up, it would not start. I was disappointed that it would not start and that it was very dirty. However, I talked the guy down a bit and bought it.
Once I got it home, I realized that it needed some repairs. First: a new air filter, spark plug and oil. I put some BG additive in the fuel to condition and clean it. I pulled the blade and ground a nice edge on it. However, it would still not start. I pulled the carburetor (a first for me) and cleaned it inside and out. Still no start. My handy neighbor was about so I asked him. We pulled the bulb and cleaned the rust out of the bottom and the fine mechanisms feeding the fuel. We put it back together. Second pull it started. It sounds great.
I still have some work to do on it. The self propelling does not work, I think it might be gummed up and the cables need greased.