I have a 1987 mercury 75 that has recently been fouling spark plugs. I have been removing them and cleaning them or just replacing them almost every time
Get a free photobucket account and upload the pics there and then link them here.
Does your electric choke fully close the butterflys? Did you pull the jets and clean them good? Allways use new gaskets when mounting the carbs.
square bowl trying to post pic? not to good at it