Every time i try to start my engine, the engine will run for about 5 seconds and then die on me. I have tried playing with the fuel ratio to try to solve this problem, but i have had no such luck. I suspect however that there may have an air-leakage around the high speed needle, as it appears that the grommets between the two parts have started to deteriorate. would this be the reason as to why my engine does not start? i really need some help! thanks