What to check when viewing used bike ?

I like to bring a compression tester with me and, if they don't mind, testing it right then and there. Can give you a good indication on the health of the top end

Check the radiators to see if they are in good shape. Not smashed or fixed with JB Weld. (And have fluid to the top)

Bearings (Wheels, linkage, steering).

Air filter and air box (Clean filter with clean air box)

Brake pads (See how much life they have left)

Chain and sprockets (extremely loose chain or rounded teeth are no good signs)

When the bike is running, pull the clutch in and shift all the into 5th gear. If it stalls, needs new clutch pack.

Thats all the major things I can think of at the moment.

If they say it's a fresh rebuild, look at the gasket areas. It should look clean and dirt free.

If they say it has a new crank, look at the split in the cases. The sealant used will be a light grey and won't be browned.

A few extras would be to pull the dust seals down on the forks. Shouldn't have oil or dirt.

The rear shock bumper really tells you how many hours are on the bike. If it's beat to hell and they say low hours, WALK AWAY!!

Also on a high hour bike, where the plastics touch the frame, the plastics will make grooves in the aluminum.

I've never done the 5th gear thing. That's a good tip if it works. Have to test this out for sure!! great tip

I pretty much expect to do a motor and all that crap right away. So for me i just look for signs it was well taken care of in general.

First thing I usually check is the air filter. If it and/or the airbox are filthy, that's usually a good indication that the bike has not been well maintained.

1e If you have the chance, run the VIN to check if the bike is not reported stolen.
2e check if the cases have no repairs on them.
3e check underside of the frame for flat spots.
4e check swingarm, look if the chain has not been worn through the chainslider into the aluminum.
5e check the linkage for play.
6e check if the wheels are straight en bearings are good.
7e check if the radiators are straight and don’t leak. Also check the fluid level.
8e Start the bike, it should start within a few kicks, ride it and go through al the gears. You don’t want it to pop out of gear en don’t want a slipping clutch.
9e check the suspension. Fork seals shouldn’t leak, chrome tubes shouldn’t have dents or damage. Check if the suspension has damping.
10e check all the wear parts (chain, sprockets, brake pads and tires) and global impression on the bike.
11e ask questions about maintenance. When was the last oil change, piston replacement, engine rebuild, suspension services etz.

Best of luck!!

The very first thing I look at on a used bike is the bolt heads. That will tell you a lot about the service of the unit as well as the care for the unit.

Paw Paw