Some problems of your blasty may be the 270jet? i dunno im just told that is reaaly big for a stock carb. get a 28 or 30 size carb and keep the same jet on it you should be fine unless it runs crappy that you can throw a bigger jet. but too big of a jet causes the fuel to air ratio to be too much fuel not enough air thus you can foul your plug, cook the motor.. etc etc