This may take a min to explain but here it goes. My 500 auto started running like @' it would idle and even get to about half throttle then it would start cutting out really bad. I was told that one of the kids had gotten old gas from a car and put it in it while I was on vacation. So once I went to work on it the first thing I done was pull the tank and carb off and cleaned them. I put it all back together and still had the same issue. Ok so while I was already working on it I needed to put bushings, ball joints, tie rod ends and new seals in the front diff. So I removed the front plastic also just to have easier access. While I was waiting for the parts to come I was trying to figure out the running issue and I found that with it running if I pulled the diode on the far right end (looking from the back) of the fuse block it would run almost perfect. So now I'm puzzled because I can't find anything that will tell me what the diode is for. Ok now skip ahead a day and I got my parts for the front and installed all of that and put the plastic back on it and went to fire it up and no spark. I have a downloaded copy of the tech manual and have ohmed the trigger coil , stator and ignition coil, plug cap , and plug wire. One thing I noticed was that it would crank no matter what gear it was in without the brake being applied. I don't think it's supposed to do that. So I'm here asking if anyone can give me any ideas about what is going on. Sorry for such a long explanation but I figured that it would help to get it all out on the table. Any help will be greatly appreciated.