I've been having a problem with Fireball glow plugs. I bought some from ebay because they had an idle bar and I was curious to see if that would work better than the Tower and OS plugs without an idle bar. There wasn't any noticeable difference in performance but the Fireballs burned out within 5 flights! I used 4 of them on 2 different engines and I keep getting the same problem. I have replaced them with the Tower plugs that I had in there previously and those have lasted all season. The engines have been running fine for two years. I'm running Wildcat 2/4 stroke with 15% nitro and 18% oil. I always have a nice trail of smoke coming out of the muffler so the engines don't run lean. Anbody have any experience with this brand of glow plug or any suggestions? I still have a bunch if the Fireball plugs left.