The engine will rotate, but it wont fire. I was backing out of a friends driveway, and the car backfired, and shut off. Usually when the car dies out, it will start right back up, but not this time. I tried tow starting it, and when you popped the clutch and it would catch, it counded like the engine was only runnning on 3or4 cylinders, no throttle response, and it died when you pushed the clutch in. I checked the spark coming off of the ignition coil, and it was a weak yellow, checked at the #1 plug, and it was the same. Went and bought a new msd blaster 2 coil, and this did not help, still a yellow spark,(shouldnt it be bright blue?). What can I look into next, duraspark box? Is there anything else in the ignition circuit behind the duraspark? Another idea I have been tossing around is that my battery drains rather quickly,I dont have a ground running off of the neg. terminal, and the battery is only a 550 cold crank,(shouldnt I at least have like a 750? My father dissgrees though). Well my question is, can a bad battery have enough power to turn the starter, but not enough to fire the engine? (it has been recharged numerous times though). Could I have a short? I have been reading a little bit about an igniton regulator, will this give me weak spark? Oh by the way I forgot to mention that I am getting gas, (for one thing you can smell it, for another,you can see it in the see through filter attached to the line on the carb. Anybody have any suggesstions, any help would be appreciated, thanks.