mike , the main jets and the power valve don't have any effect on the idol of an engine.. on a six pack setup, you need to get both outboard carbs fully closed. check the linkage adjustments. then - close the idol mixture screws on the center carb untill lightly bottomed out . then open them up 2 turns each and you will be ok. open the screws for richer idol mix and close them to lean it out . the engine idols off of the center carb only. one of the most common problems is dirty needle /seats and mis -adjusted floats . it will make the the carb flood. take out the needle ,look closley ,blow it off with a shot of air , and re-set the float level . i know it seems basic but, you will be supprised how often it is that simple.. hope it helps . BW.
