My friend found this - hope it's of use.  There's another checklist here; http://www.clarity.net/~adam/buying-bike.html

 USED MOTORCYCLE CHECKLIST

Static Tests

Title

•VIN matches title   Y     N

•Bill of sale with seller name, vehicle #, amount, etc.

Appearance

•Is bike clean? (shows bike owner cares)        Y     N

•Body scratched and/or dinged? (shows possible dumping)    Y   N

•Lower engine cases scratched or dinged? (shows dumping)         Y     N

•Fuel tank has rust inside?        Y     N

Controls

•Brake levers bent? (Shows bike could have been dumped)    Y     N

•Throttle twists only with high resistance? (shows problems with carbs, bars or cables)     Y   N

Tires

•Tires have at least 2-3 mm of tread left? Y        N

•Tires are old and hard or have cracks?            Y     N

Wheels

•Both wheels spin freely?        Y     N

•Both wheels round? (Spin and sight)         Y     N

Lights

•Headlight works on both high and low beams?     Y        N

•Turn signals work front and rear, right and left?  Y     N

•Brake light works with both front and rear levers?        Y     N

•Oil pressure light comes on, goes off when bike cranked?        Y     N

•Neutral indicator light works?     Y        N

Brakes

•All pads have at least 2mm left?          Y        N

•Master cylinders fluid color?      clear         cloudy brown     

•Apply and release brakes, check for drag:        Y     N

•Wheel hoses, any leaks, cuts or cracks?        Y     N

•Hold front brake lever, any fade?          Y     N

•Hold rear brake lever, any fade?          Y     N

•Apply one brake at a time, try to move bike, any movement?        Y     N

Chain

•Even tension throughout? (spin slowly and pull top and bottom)     Y          N

•Properly adjusted and lubed?         Y        N

Sprockets

•No hooked teeth front and rear?        Y        N

•Chain aligned front to rear sprocket? Y        N

Oil

•Color:         -honey (new)

                -black (old)

                -metal flecks (engine damage)

•Smell:              -gas (engine damage)

                -burned (engine damage)

Forks

•Bounce 2 times, any seal leaks?               Y     N

•Shake side to side, any play?         Y     N

•Sight down tubes for straightness, any bends?        Y     N

•Pitting and/or gauges in slider tubes?              Y     N

Swingarm bearings

•With rear wheel off ground, shake side to side, any play?    Y   N

Rear Shock

•Push down on grab bar / rear seat hard, does rear end rise and return quickly but with a bit of resistance?         Y     N

Steering head bearings

•With front wheel off ground, see if wheel will point straight ahead, is it easy to do? (indicates worn bearings if it does)        Y        N

•From handlebars, able to feel any grinding, roughness or detents in bearings?  Y        N

Spark plug wires

•Cracks in plug wires?      Y        N

•Pull plugs, color black? (indicates burning oil)         Y     N

Exhaust

•Any rust holes through pipe?         Y     N

Battery

•Corrosion on terminals? Y        N

•Level topped off?  Y     N

Air filter

•In place?         Y     N

•Clean?    Y        N

Operating Tests

Starting

•Start bike cold (feel crankcase to confirm), starts easily?        Y     N

Idle test

•Let bike warm, any unusual noises?       Y   N

•Will bike idle smoothly without hesitation or stumbling (carb problems)?         Y       N

•Does bike produce blue smoke? (burning oil)              Y     N

•Any oil or coolant leaks?        Y     N

•Turn bars, does engine RPM rise? (throttle cable problems) Y        N

Acceleration

•Is bike crisp on the throttle?     Y     N

•Is bike power good on hills, including starts on hills?    Y        N

Braking

•Does front brake stop firmly?      Y        N

•Does rear brake stop firmly?                 Y     N

Slow speed steering

•Does front end wobble in slow, tight turns?         Y     N

Transmission

•False neutrals?                Y        N

•Difficulty in 1-2 shift?  Y        N

•Engine brake, does transmission pop out of gear?                Y        N

•Close throttle quickly, does transmission pop out of gear?                Y        N