I got a riding mower from my aunt, I was the last one to use it last year and it had trouble starting but when it started it stayed running but now it won't. It has a 15 hp ohv briggs and stratton engine, when I got it home I tried to crank it but it kept hanging on the comp. stroke so I did some research and then I set the valves to .005 on intake and .009 on exaust, set magneto to.010 and now it turns over and starts great but won't say running, PLEASE HELP??

Hi,
Generally that would mean a dirty carb or fuel filter. Could however indicate a obstructed fuel line.
Peace,
Clarke