People, people, people..... i have installed new NGK plugs in my 1999 Mercury 115.....went to the lake, the motor idled rough, sputtered taking off but finally smoothed out at WOT. This is unlike the motor performed prior to changeing the plugs. While on the lake I changed back the the identical plugs I removed, and the performance was back to normal.What did I miss??? I noticed oil on the new ones I removed.... i did not gap the plugs.... I think this is the problem but want to find out what are the best plugs to install, and the gap.... any help would be helpful and apprieciated.... its cold in GA... and I am getting Stir crazy and working on everything I can.
