Ive been having some problems with my wifes bike. It starts sometimes and sometimes its really hard to start. it spits and sputters and dies. when it runs it runs good but then all the sudden it acts as if it runs out of gas. but the carb and tank are clean 5 or 6 times over. the gas cap is clean. Im thinking its a spark issue. is there a way to determine if its the coil, cdi, or stator,etc. is going out? I pulled the plug when it was having one of its spells and the spark seemed week and random which would explain the spitting and sputtering.