Oldfeller--FSO wrote on 05/22/12 at 18:27:21: Stupid assumption on my part -- you took the engine apart at some point in time.
Quick question -- IF SO did you hone the bore lightly to break the glaze and put a set of cross hatch scratches on the bore surface?
If you've never had it apart (and the PO didn't have it apart) then you are looking for an internal leak (should be burning oil) stiffened valve seals (should be burning oil) or stuck rings (should be burning oil).
<evil chuckle>Bill missed one -- what sort of oil are you using?
Routy missed one -- if you were using the list side stand oil check method instead of the Suzuki method you wouldn't have run out of oil like that .....
Motor was never taken apart. The bike is only 5 years old, and only has 1600 miles on it, so no reason to. Only taking apart I did was to remove left and right side covers to powder coat them black. I also did the cam chain tensioner upgrade.
No work was done to top end, valves, etc.
I am using plain Castrol 4 stroke motorcycle oil- 20W-50. Non synthetic.
I have attached a picture of my plug as it looks today.