[john70t]

FUEL
-Smell of gas in the carb or tailpipe? Then it's ignition related, or too much fuel.
-Change the fuel filer if unknown, and write the date on it .
-Choke should be closed when cold, and fully open when warm.
-Put your hand over the carb(making a choke and pulling in more fuel). If it runs better then the mix is lean. Playing with the mixture screws is a bandaid for the the real problem

SPARK
-Check the battery using a DVOM. Should be around 12.6V after sitting a while, and around 13V just after running.
-Check the alternator output (DVOM still on the battery) at 2,000rpm. Should be around 13-14.5V.
-Battery connections and ground strap should be clean and tight.
-Unplug each wire and use a spark tester grounded against the block while cranking. All should be equally bright. Disconnect the electric fuel pump or pull the fuse first so that it doesn't flood the engine.

MISC
-Shine an infrared thermometer on each exhaust header. They should all be burning equally hot.
-Shine an infrared thermometer on the tailpipe before and after the catalitic converters. It should be 100+deg hotter after.
Rotary/Wankel engines burn dirty, so to pass federal emmisions Mazda put multiple catalytic converters on them