Buying Used Dirt Bike
Maybe it’s time to buy a bigger bike, or maybe you’re after your first bike – but now it’s time to decide whether to buy new or used. Used can definitely save you money, but a lot of (potential) riders don’t feel confident enough to spend money on what may be a lemon or damaged goods. The following tips and advice should give you the information you need, and boost your confidence when buying a used dirt bike.
Decide how much you want to spend BEFORE you start looking. It’ll help narrow down and speed up your search, and it’ll keep you from paying more than you can afford. It’s no fun having a bike you regret owning.
No matter how excited you are to own one, don’t buy the first bike you see. The more used dirt bikes you look at, the better you’ll get at it. An exception to the rule would be if you have someone experienced with you.
If you’ve targeted a used but newer model, you’ll probably find reviews in back issues of magazines or online. If that fails, get the opinions of other riders on various dirt bike and motocross forums.
Generally speaking, a used dirt bike is cheaper from a private seller than a dealer.
Watch out for “private” sellers who are selling a number of bikes at the same time. They may be unloading over-priced junk they picked up somewhere else.
If a deal seems too good to be true, it probably is. The dirt bike might have some hidden damage or even be stolen. Check to see if any registration or serial numbers have been removed or altered. If they are, walk away – and let the police know so some other buyer doesn’t get taken (and maybe the REAL owner will get his bike back).
Remember the dirt bike probably looks better on the day you’re looking at than it has in months or years. The seller will shine it up and possibly replace cheap parts. Check the ENTIRE bike for wear and tear.
Fluids dripping from a bike are always a reason to look closely and dig deeper.
If the seller is reluctant to let you take it out of sight (some bikes have been stolen during a test drive) let him hang on to your drivers license and car keys. Bring a helmet for the test ride. If you brought your experienced friend, let him or her take it for a spin as well.
When you’re shopping, keep track of the prices people are asking for similar bikes – it’ll give you a better idea if you’re getting a fair price.
Let the seller talk. Often, the more you keep your mouth shut, the more they’ll say (human nature). They may give out information you wouldn’t get otherwise.
Don’t be afraid to ask the obvious questions – was it raced, trail-ridden, any crashes, major repairs, how often was the oil changed. An honest seller will understand why you’re asking and won’t mind answering.
Don’t nickel and dime the seller over minor things like scratches and decals. The bike’s USED. You can mention obvious problems and needed repairs and intelligently work it into your offer. Remember, the seller has probably dealt with a lot of jerks already – you’ll get along better and get a fairer price if you’re reasonable and honest.
Once you make the deal, but before you pay, don’t forget to ask about any manuals, receipts, and spare parts they may have. If the bike has a key, obviously make sure you get one, but ask if they have a spare (and if they don’t, get one cut right away!).
If you’re lucky enough to have an experienced rider as a friend, by all means bring him or her along. Their experience is obviously valuable, but so is the extra set of eyes. If you can, narrow down your search and get their opinion before making your final decision – that way you can use less of their time. And buying your friend lunch is well worth it if it saves you from making an expensive purchasing mistake.
If someone experienced can’t come with you… go to them. When they have some spare time, ask them to go over THEIR bike with you, front to back. They’ll give you a great idea of what to look for, and where.
If the seller claims work has been done in a shop, it’s reasonable to ask to see the receipts.
After-market paint is a warning sign! Ask why it’s there.
Racers often use safety wire to keep bolts in place. Small holes through bolt heads are a good indication that the bike has been raced.
Sometimes after-market stickers and decals are slapped on to hide damage or defects. If it seems like an odd place for a sticker, take a closer look.
Honda? Kawasaki? Well-known names? Names you’ve never heard of? 100cc 4-stroke? 250cc 2-stroke? How do you decide which dirt bike to buy?
Try and ride as many different bikes as you can. If you have a bunch of dirt biking friends, this gets easier. If not, check out which dealers offer a try before you buy approach. A lot of rural dealers have a field or track you can take bikes for a spin on. A bike you’re comfortable with is one you’ll ride better and more often.
Different makes of bikes have their own quirks and problems. Check out reviews where you can (online tends to be the easiest for used). Ask people who are already riding. Go to dealerships and ask why their models are better than the competition’s.
Ask the seller to not start the bike before you come to look at it. If the pipe or engine feels warm when you arrive, chances are it has trouble starting cold. Carefully check the engine case (in case it’s hot) instead of the exhaust. The exhaust gets hotter, but the case will stay warm much longer after running.
The engine should start fairly easily with, at most, a few kicks.
An engine that’s hard to start could be something as simple as fouled plug (easy and cheap to replace) or as complicated as an ignition or compression problem (potentially very expensive and/or time consuming). Assume that if it’s a cheap/simple fix, the seller would have taken care of it already.
It’s normal to need some choke when starting a cold engine. Later, when the engine is warmed up, choke shouldn’t be required.
Loud metal-on-metal sounds are a warning sign. Politely thank the seller and walk away.
If it sounds like something’s vibrating, try to track it down. It could be loose mounting bolts, number plates, etc.
There shouldn’t be any hesitation when twisting the throttle.
Test the throttle cables by turning the handlebars fully to one side and then twisting and releasing the throttle. It should snap back on its own. Repeat the test with the handlebars turned fully in the other direction, and in the center. If it sticks or returns slowly when cranked to one side, it’s probably a cable routing issue – not too hard to fix. If there’s resistance in every position, it could be a carburetor problem, a bent handlebar, or seized cables. If the bike is running in neutral, and the engine revs when you turn the handlebars without touching the throttle, it’s most likely due to poor cable routing.
Some bikes use a fuel pump which needs to build pressure before the bike will start. These bikes will have an ignition switch. When you turn on the ignition, you should hear a hum from the gas tank. The bike is ready to start when the humming stops.
All those moving parts in an engine need to seal tightly to work properly, and to keep fuel from mixing with oil and coolant. Compression is basically a measurement of how tight the seal is in the combustion chamber.
The best test is with a compression tester, but this isn’t always an option. Instead, try this: turn the engine over with the kick-starter and, if it feels harder to turn at certain points (almost like it’s sticking) -- you're getting compression – that’s good. If it feels loose all the way around, you probably have compression problems.
If you can’t take the bike for a spin (and you really should), put it up on a safe stand with the rear wheel off the ground. Shift through all the gears to make sure they all engage. Idle speed is fine and keep the front brake locked in case the bike slips off the stand.
Check the transmission fluid level. There’ll either be a site glass (a little “window”) or a dipstick. The dipstick is often bart of the filler cap. After the bike has been off for a few minutes, make sure it’s standing level front to back and left to right. The level should be in the safe range of the dipstick, and between the upper and lower edges of the sight glass. It would take a pretty stupid seller to not fill the transmission properly before showing the bike, so if it’s way too high or too low, that’ll tell you something.
You’ll have to judge how honest you think the seller is, but ask how often the oil was changed. A lot will depend on how often and how hard they rode the bike. The motocrosser who races every week will need far more changes than the trail rider who heads out for a couple of hours once a month.
Drip some oil onto a white piece of paper or paper towel. Black is the normal color after use -- ask how long ago it was changed. A clear gold color means it’s new, recently changed – is the buyer hiding something? White milky streaks means water, probably coolant, is leaking into oil – there’s a defective seal somewhere (check the coolant section). Greyish oil is usually the result of a lot of aluminum particles – not a panic situation on a dirt bike in some people’s opinion, but not something I like. Shiny flecks in the oil are bits of metal – something is wrong.
If the bike you’re looking at has a radiator, it’s referred to as liquid-cooled. No radiator means it’s air-cooled.
If it’s liquid cooled, check the radiator for bent fins or crimped fittings, or major dents.
Check the coolant level when the bike is COOL. If the engine is hot or even warm, you can burn yourself severely.
Obviously if the coolant level is very low, or there’s no coolant, that’s a bad sign.
If you found white streaks in the oil, it could mean that coolant is getting into the transmission, or it might be condensation from the air in the engine. White streaks from condensation should disappear after a half-hour of riding.
Coolant in your oil is the result of faulty gaskets or worse. Something worth looking into and fixing if you already own the bike – not worth the risk or hassle if you’re buying it.
The coolant should have green, almost glowing color to it – this will be antifreeze mixed with the water. Antifreeze is formulated to keep the water from freezing AND to raise the boiling point so the bike doesn’t boil over. A 50/50 mix is typical. Straight antifreeze is BAD.
Straight water means the coolant system hasn’t had the benefit of corrosion inhibitors.
Brown or murky coolant is caused by oil or rust. Rust on the inside of an engine is bad. Oil leaking into the coolant is bad.
A dirt bike might put out some white smoke from the exhaust as it’s warming up, but exhaust gasses should pretty much be invisible once the engine and exhaust pipe are hot. White smoke from a warm engine usually means a bad head gasket.
Blue smoke from the exhaust indicates the engine is burning oil. This is normal for a 2-stroke since oil is mixed in with the fuel. The smoke should decrease as the engine warms up, but won’t disappear. Excessive amounts of smoke bear looking into.
Black smoke usually occurs when the engine is running rich (too much fuel, not enough air).
Check for holes, cracks, significant dents. On two-strokes you can often spot even pinhole leaks by the oil that seeps out.
Mufflers/silencers/spark arrestors need to be repacked occasionally. The only real way to tell is to know what the bike should sound like -- louder than normal and it probably needs repacking.
With the bike in neutral, roll it forward and gently apply the front brakes. The lever should move easily and the brake should engage smoothly. Then release the lever and ensure the brake isn’t dragging.
If the front brake lever comes all the way back to the bar with very little, or no resistance, something’s out of whack. If you know how to adjust the lever, you can try that. The fix may be as simple as bleeding the brake or something far more expensive. When in doubt, move on and look at a different dirt bike.
To check the rear brake, straddle the dirt bike, roll it forward and push the lever down. The lever should move smoothly, and the brake should engage evenly.
If the brakes are drum brakes instead of disc, you’ll have to open them up to check pads and drums. Pads are fairly inexpensive.
Look into the calipers on disc brakes. There should be at least 1/8" of brake pad material on each pad.
Rotors can be warped. If you can see the warp with your eye, it’s severe – move on. A test ride will help you feel any slight pulsing a warp would cause.
Check the rotors for grooving by dragging your fingernail across it.
Check the brake hoses for damage and leaks.
With the bike in first gear, squeeze the clutch all the way in and roll it forward. It should feel like neutral, although there could be a little more resistance. Slowly let the clutch out and feel for the friction zone. Clutch engagement should be fairly smooth, not abrupt.
If the lever feels loose and moves a little, it could just be the cable adjuster (on the cable, next to the lever) needs to be turned.
Look for dents in metal tanks, and creases in plastic ones. Minor damage can be expected on a used bike, but watch for anything that indicates a big crash.
Look for rust inside metal tanks – use a flashlight. Rust can clog your carburetor.
Look for any kind of sediment in plastic or metal tanks. Sediment can clog your carburetor.
Gas that’s the same color as a mug of coffee has probably been sitting in the tank for a long time. Chances are good you’ll have to clean the fuel system and carburetor.
Expect the seat to be worn. The older the bike, the more wear.
Rips and tears can let water into the foam if it rains on your bike, or you ride it (or fall over) in water. You can do an effective, but so great looking recovering on your own… buy and install a new seat skin that will fit and look a lot better… or send the seat out to be done.
Make sure the seat is fastened properly. Give it a shake.
When you test ride the bike, try to find some flat ground. Rhythmic thumping or shaking that changes pace to match your speed can be caused by unbalanced tires or flat spots.
Check for obvious damage and excessive wear.
If you’re not going to be competing, you can have quite a bit of wear on your tires without affecting performance too much.
Make sure the kill switch works.
Check connection on plug wire.
Follow all wires and look for breaks, or places where the insulation is worn through.
If the bike is equipped with an electric start, make sure it works. If the battery is dead, don’t even think about buying the bike until you can come back and try it when the battery is working. The dead battery could be a poor attempt to hide a more serious electrical problem.
If it’s a dual-purpose bike with headlight and signal lights, check them out. Bulbs are cheap, so if a light is dead assume it’s something else (otherwise the seller would have replaced the bulb).
Watch the headlight while revving the engine. If it gets brighter at higher revs the battery could be dead or close to dead, or the voltage regulator could be shot.
Hold the front brake in while straddling the bike and push down on the front forks. They should compress and come back up with slight resistance.
Press down hard on rear of bike. Suspension should compress and come back up with slight resistance.
Fork surface should be smooth and free of damage or fluid leaks.
Rear shock should be free of leaks.
Get the bike up on a stand and try to move the swing arm back and forth (not up and down), and try to move the front forks back to front, front to back. If you have a lot of play on either, there could be worn bearings – an expensive repair.
Check rims for visual damage.
With the bike on a stand, spin the wheels. Dents and warped rims are easier to spot when the wheel is spinning. Find a stationary part of the bike near the wheel and watch as it spins – it shouldn’t get nearer or farther at any point in the rotation.
Front wheel should spin freely with hardly any resistance at all.
Rear wheel should spin freely, but will slow down quickly because of chain friction.
It’s tedious, but wiggle each spoke. Lots of loose or missing spokes indicate a lack of maintenance. A couple of missing spokes are easy to replace, but depending where you can get parts, some places only sell entire spoke sets, not the one or two you need.
CHAIN (& SPROCKETS)
Hopefully you remembered to have a rag handy. Grab the chain at the very back of the rear sprocket and pull. If you can see more than half of a sprocket tooth, you’ll need to replace the chain or sprocket.
If the sprocket teeth look hooked (like claws), they’re worn. The teeth should look the same on both sides, as should the gap between the teeth. If you roll the bike backwards and hear a clicking from the rear sprocket, it’s probably hooked.
The chain should have about ¾-inch play in the middle, at the bottom. Exact amount will depend on individual bikes (check the manual) but what you’re looking for is excessive tightness which leads to excessive wear, or excessive slack which indicates poor maintenance.
Check for cracks in the frame and in welds, and if it looks like there’s a weld where one doesn’t belong, compare it to another bike.
This video is also worth looking at.