looking for a chart of some sort, if any, to tell me where my timing marks should be. i think she jumped time on me. she's puffin a puff of raw fuel out the air filter end of the carb (in time with the "roll over"). and not to mention she won't crank. ran fine yesterday, but still lies where i parked her. one of those "was running great, now won't even crank" type deals. any thoughts? experience with this?