hi im new to this site, i recently got an 04 blaster, that was supposedly rebuilt, it wont start i checked for spark with an inline spark tester, i cleaned the carb it looked ok, all jets were clean, i looked at the reeds they looked good, i checked the crank key and flywheel it looked ok. engine has good compression. it does have a reed valve spacer. i can get it to start but i have to kick the crap out of it and you have to hit the throttle just rite to get it to fire, and sometimes it backfires through the carb. its almost like its out of time. please help!!!!