Just put a snorkel on the carb intake on my 325 magnum 4x4....it is the same diameter as the filter and a total of 6 ft in length...Idles fine,but at 1/4 to half throtle it "bogg's"....Although I am pretty handy working on things I know NOTHING about jetting/rejetting a carb.I am assuming this is my problem....Do I go up or down in size.....and how much????Thanks