Along with Scott's advice, here are my 2¢:
Motorcycle test ride points:
1. throttle in first gear
2. suspension
3. braking
4. weight
5. helmet lock
6. capacity under the seat
buying a bike:
oil level should be within range of it is side glass. and should not be over filled.
exhaust must be cold, not hot(make sure he didn't start the bike for you and keep it warm, before you visit him)
vin numbers should match with engine/frame.
look for accident scratches everywhere.
look for chain tight spots and whether S/he maintained well or not.
brake pads and rotor for Wear level.
throttle should be loose/s mooth and should return smoothly
tires should not be worn out, else negotiate 250$ more
test ride:
transmission must be smooth while shifting gears
no shaking in handle bars when riding off hands(for experienced riders), check at 40mph, for balancing.
These were my notes from last year, before buying the bike.
Hope they help.
BTW, if you post the same on fz6r forum, they might say to look for something particular, based on the model's year.
For instance, people from Acura TL forum mentioned to look for oil level, as 2010-12 models tend to consume oil and see a decline in oil level for every 1000miles.