I have been working with this for a few months now and got it to the point that I was finally able to start it with the starter. I took apart my tsx458 carb, cleaned it well and replaced some parts. A week ago I used it and noticed it was running a little rough, popping and backfiring. Thinking it was the carb, I had this issue before, I took it apart because the float likes to stick. Didn't see any issues. Before trying to start it again, I looked over the electrical end. The points came loose and was not opening all the way. This explains the backfiring. Now everything is as it should be so I try to start it. Won't start. I get out the starting fluid and it fires right up, then dies right out. I played with it for about 30 seconds and it would only run with the starting fluid. Then it stopped running altogether. I have been able to get a cylinder to fire but that is it. I am just confused that this is not running at this point. I should also add that when it did run, it ran smooth. Could the use of starting fluid have done something not good to the engine? I couldn't help but notice that when cranking afterwards, it sounded almost like there was little resistance.