I have a mid 70´s RV125 I´m trying toget running. After several miles it gets hot and dies out. Something is up with the carb I think. I took it apart and cleaned it. It wants to run very rich. I have to slap the choke on once in awhiel to keep it running, then flip it back off. I richened the carb adjustment screws as well. The tach says it´s running at 5k although I´m doing just 20-30 mph in high gear. Timing? Points?