The ballpark settings for that size engine are 1.5 to 1.75 open on the low and 1 on the high. Remember that the engine always sucks from the low needle so if it wont transition from this base setting and your ending up with the low 4 turns open you've got a problem. Either you have a fuel blockage or if the carb is old the diaphrams dry out. If the carb if fairly new clean it out with compressed air but if its old I would put a carb kit through it before you bury it.