sportster vibration

IF ANYONE HAS A SUGESTION i WOULD APPRECIATE IT. MY WIFE HAS A 01 SPORTSTER THAT ALL OF A SUDDEN STARTING VIBRATING SO BAD AT AROUND 3000RPM IT IS VERY UNCOMFORTABLE FOR HER TO RIDE. NOW i KNOW SPORTSTERS VIBRATE BUT THIS ONE WAS NOT THAT BAD UNTIL RECENTLY. I have checked tires belt all motor mount bolts. I changed handlebars and bushing. This helped but the seat is still bad.The bike has a voyager trike kit on it but the problem exist sitting still in neutral. So that isn't the problem. Thanks Sugar Bear

I'm assuming the obvious, and that she didn't happen to get bad gas or something... That, and did you check spark plugs? I'm no expert, but those are the only (obvious) things I could come up with.

I'm assuming the obvious, and that she didn't happen to get bad gas or something... That, and did you check spark plugs? I'm no expert, but those are the only (obvious) things I could come up with.
Sometimes it takes someone standing back to look at things thanks I haven't checked the sparkplugs and come to think of it she changed them right before this happened. thanks for waking up a dummy