New plugs and Throttle body sync helped somewhat. May have valve clearances checked, adjusted this year.
Appreciate the reply. I've done the following:
-New plugs correct gap and torque.
-Tb sync
-New bridgstone t32gt's, got rid of the Metzler z8's that caused a very noticeable vibration at certin speeds. Well documented on this site.
-New front and rear bearings using nsk sealed units. Correct reinstalation procedure was followed using 2008 setup guide. Everything torqued to spec.
-axles lubed with thin layer of m1 synthetic grease.
-clutch fluid flushed per manual.
-All brake calipers cleaned, lubed, inspected and reinstalled per instruction in repair manual and on this site. System blead. Get two rotations on rear and two on front with solid 'push' on the tire.
-counter balance adjustment done.
Have put about 400 miles on this year so far, running 91octane non oxginated gasoline and redline si-1 to help clean out the system.
Went with Motul V300 10w40 in hopes the ester based oil would help.
I still have vibration and a rhythmic thump that is directly related to speed at which Im travraveling. While stationary in the garage, st on its center stand, a thumping can be felt in the handlebars that dissapears with the clutch lever pulled in. It also increases and decreases with rpm. Thinking the next step is to inspect the shaft drive assembly. possibly transmission output shaft (really hope its not ) 2004 with 23,000mi on the clock, just picked it up April 7. Previous owner had not ridden it in over a year, swears it was "smooth as silk" when he parked it.