my m8 has a 1991 yz 125. i just put a new piston+ring in it when it started it was sweet but after 2. 15 min run ins the bike will not start. tried new plug weak spark got new stator plate still no good got new flywheel + cdi + new coil the bike has a good spark now but will not fire the timings right. when u kick the bike it does not pop bang or fire had the carb checked ok. please help thxs