Hi guys am having trouble on my top cylinder it keeps missing i put a new set of plugs in it and it went great for a month! and unfortunately they have fouled again i suspect its runnig way too rich on the top cylinder is this possible? and how can it be adjusted? i took the plug out cleaned it and it was running shlightly better but still bad again the plugs are $50 a set so im not too keen to keep putting them in any advuice how to fix this plug fouling problem?