over the past few years it has became very difficult to start. I took the carb all apart and seemed a little better. Some times pops like old gas but is not. Thought maybe the ignition was weak? A couple of times i had someone pull me until it started to fire. Usually longer than 100yards before it would even try.would an aftermarket ign ensure easier starting? Any suggestions on where to start. If the compression is low would it act like this?