Need to balance the carbs and take another reading. This can get deep (or long), but if your just riding along and easing back to the house and checking the plugs, you are going to have a hard time finding the rich and lean points. Pat (Dinqua) is right on with all his info, but when checking the plugs you need to chop the throttle and check them. that means take the bike out (mark the throttle) and run it a mile or so at 1/4 throttle. Grab the clutch and hit the kill switch. Pull over and check the plugs. Thats a throttle chop. Do it at 1/4, 1/2, 4/3, and WOT (or save yourself a ticket and use a dyno). Any gear works.
But, above all, balance the carbs every time you make a change. My left carb is a 1/4 turn richer than the right.
