At the end of last year I bought a 2016 Burgman 650 Exec with 31K miles and have been getting it ready for the summer. My last task was to replace the spark plugs. The plugs that I removed were in horrible shape. I cleaned everything up and installed the new NGK plugs. However, I could not reinstall the ignition coils....they just would not go in far enough to seat properly. Finally, out of frustration, I pulled the new spark plugs out to see if I could determine the problem by re-seating the new spark plugs onto the ignition coils at my workbench. However, the new spark plugs now had "caps" on them like car spark plugs. I unscrewed the caps and tried to re-install the new plugs into the ignition coils but I could only do so if I screwed them in....I could not simply push the plugs on. Any thoughts as to where the caps came from or why the ignition coils are so tight threaded that I cannot push onto the spark plug posts?