Greetings all. I have a GT5 on my mountain bike. I have 125 miles on it. At first, I had rubber in between the motor mounts. Well that vibrated the carb so bad that the it broke apart the mounting ring on it. I bought a new speed carb with made it run much better than the High efficient carb it came with. Also, the vibration had busted both of my rear motor mount bolts. I could not get the bolts out, so I drilled and threaded 2 new holes, which also aligns my drive chain better. The ignition wires had touched the muffler and melted some, but the motor was still running good. Now, after running for about 10 minutes, the motor dies as if not getting spark. I have spliced in new wire where it had gotten hot, but my problem still exists. When it starts acting up, it also backfires. I have adjusted the needle valve in both directions with little change. It seems to work best in the leaner position. Can anyone help me with this?