Running odd, Lagging, Hesitating. ??

[jen_]

I hate to post such a dumb question, but hopefully I have made up for it with other, less flakey posts...

My bike is running crappy.  I notice it especially in town, accelerating.  It has that boggy, hesitating feeling, like it is running out of gas.  It's subtle, and I thought I was imagining it at first.  It has gasoline, petcock on "On".  Sorry I can't be more specific.  The engine/exhaust system are stock w/about 5K miles.  I thought maybe it was bad gas, but I ran through most of the tank then refilled with 89 octane gas not from Circle K.

I hate to take it to a mechanic with no ideas about what to do, for fear of getting hosed.  Any suggestions are appreciated.

[ajgs500]

Valve adjustment??? 

[scratch]

At what rpm's is this happening?

Is it happening in all gears?

Have you had the valves adjusted at 4k miles?

[jen_]

Nope, haven't had the valves adjusted, thanks.

Noticed it today again-- most noticiable in 3rd gear, around 5K RPMS, 45-ish MPH, and mostly when slowing or closing the throttle.