[Fyter87]

Well I would get everything Checked out first. Sounds like the coil could be going or your distributor cap is wack and is not getting the proper spark.Also Possible you might need some new spark plugs. I would basically change everything that has to do with the electrical for running the Engine. (Distributor, Distributor Cap and rotor, Coil, Spark Plugs and Wires) If you feel confident and know what to look for. I would just check it out for yourself if your a hands on person. Those are things I would look at and fix if nessary. But if your not to sure, I would bring it to someone. Plus you said it was back firing, could also be something with fuel too. Either getting to the Carb or somethings wrong with the fuel pump. Just make sure to get it checked out. Hope this Helps!! Take Care.