The best advice for checking out a used motorcycle is: take along your mechanic! The second best advice is to educate yourself as much as possible. Here are some basic things to look for to help you think along the right lines:
A seller will probably NOT let you ride the bike, but there are things you can do to check it out without riding it around. The basic idea is: You want to get the bike’s “story…”
Has it been in an accident?
Bikes get tipped over, and dropped, and even crashed (and repaired)…and run fine afterwards. But before you buy anything you ought to know if that’s the case just so you know what you’re getting into. A tip-over while parked or even a low speed drop doesn’t need to be cause to walk away, but a crash may be… So how can you tell? Look closely at the paint, the bar ends, levers, foot pedals… A repaint is a dead giveaway that the bike’s been in an accident. Generally the rule about scratches are: long parallel scratches probably come from a moving fall, while short scratches and dings come from tip-overs… You need to think like a detective here. Dents usually happen from tip-overs, but handlebar dents (dents causd by the bars hitting the tank) are often the result of a crash.
How’s the engine?
Before you start the engine, check to see if it’s cold. A warmed-up engine can hide some of the irregularities that a cold start would bring out. Once you start the engine, how does it sound? It helps to know what a healthy engine sounds like at this point. Different types of engines sound different: Ducati twins sound like they’re stumbling and just barely coming to life when cold started, whereas fuel injected inline-fours should have a soft hum. Give it a little gas and listen for knocks or pings or any irregularities in the sound. If the motorcycle has a choke lever, make sure it works okay.
With the engine off, check it visually for signs of leaks, rust, or areas that look like they’ve been cleaned or fixed recently. Check the inside of the gas tank with a flashlight to see if there’s any rust… Any rust or signs of leakage on the engine or inside the tank are bad signs, walk away! You may find surface rust spots on the side stand or parts of the exhaust, these are no big deal, but the engine should be free of rust or leaks of any kind.
How is the transmission (and brakes)?
With the engine off you can sit on the bike and put it into first gear. If it doesn’t go into first right away, just let go of the clutch and roll the bike in neutral (back and forth) for a moment and then hold the clutch while putting it in gear. Once it’s in first you can hold the clutch and roll the bike while releasing the clutch to get a feel for how it grabs. The wheels should grab toward the end of the lever’s release . Try clicking through the gears while rolling back and forth (note: on some bikes it’s not possible to click past neutral, that’s okay).
You can do the same, rolling the motorcycle back and forth, to test the brakes… You can get a pretty good feel for the front brake doing this. Also you can check the brake pad and rotors visually: check to see there’s some life on the pad, and that the rotor is smooth and free from blemishes. If the brakes don’t stop smoothly or feel spongy that’s a warning sign. Bleeding the brakes to remove an air bubble is no problem, but you need to find out “how” it got that way.
How are the tires, wheels and chain?
Look at the tires to see how much tread wear there is. If the bike is low mileage, check for dry rot in the tires. If the tires do need replacing, that’s not a deal breaker, but you want to take that into account when you negotiate the price. Look closely at the wheels for any cracks or damage.
The chain is often a matter of pride for motorcycle owners. It needs to be cleaned and lubed regularly. Although it is easy to replace, the condition of the chain can tell you how the owner has taken care of the rest of the motorcycle. It should be clean and rust-free. Also, look at the sprockets: are they rounded (worn down) or pointy?
Look at the teeth on the sprockets. Have they become curved like cresting waves? Are the sides of the teeth worn? A yes answer for either question says that a sprocket’s days are history. As a rule, replace both of your bike’s sprockets and the chain at the same time. If the sides of the sprockets are worn, the rear wheel is out of alignment. (Sportrider Magazine)
These are signs that the bike has gotten lots of use and the sprockets (and chain) need to be changed. These are not deal breakers and but you’ll want to address this when you negotiate the price (chains run roughly from $180 to $300 plus another $60 to $120 for sprockets…and labor if you have a mechanic do it).
How about the shocks?
Look down the front forks to make sure they are straight (bent forks are a common result of crashes). You can also test the forks by sitting on the bike, and while holding onto the front brake, pushing down on the handlebars to compress the front forks and feel its rebound. A healthy suspension should compress and rebound (to its initial resting point) smoothly and quickly without bouncing after returning to its initial position. Sit on the bike and use your weight to check the rear shocks in the same way (while holding onto the front brake).
What else can you do?
There’s much more a mechanic could look for, but apart from that you can simply talk to the seller and see where he/she is coming from. Why are they selling? You can ask straight out, “Is there anything I should know about the bike?” “If you were to keep it, is there any work you would do on it?”
Having done these simple checks you will have a sense of the bike’s “Story.” If you have a bad feeling about something, simply walk away. There will always be another “perfect” “great deal” bike on Craigslist… Happy bike hunting, and ride safe!