Used ATV Buyer's Guide

Chain and Sprockets
The first thing to check when looking at the chains and sprockets are the chain adjusters (if there are any). If the adjusters are almost out of adjustment then you will soon be replacing chain. This isn't a big deal in itself but you should also check the adjusters and sprockets for wear. If the adjusters are a teflon / nylon sliding or rolling adjuster make sure that there is plenty of material left on the adjusters. If the adjusters are sprockets with bearings make sure that there isn't much side-to-side play in the bearings and that they roll freely. The best way to check the chains, adjusters and sprockets is to have at least one side of the ATV off the ground so you can watch the chains move as you manually rotate the tires.

When you spin the tires listen to and watch the chain / sprockets carefully to make sure that you don't hear any popping or grinding. Both can be indicative of misalignment or worn componants. Also take a close look at all of the sprockets and see if any of the teeth look worn. Sometimes instead of replacing chain when it is worn owners incorrectly take out a link or half-link of chain to get back the adjustment. While this seems like a quick and cheap short-term fix it actually can wear the sprockets out.

When inspecting the sprockets look for teeth that are shaped differently on the drive side of the sprocket. Instead of being straight the teeth will be curved or bent in one direction aka "shark fins". If the sprockets are held in place by bolts through the axles make sure that the nut is tight on the sprocket tube and that the the holes are not elongated. One problem you see with bolted sprockets comes from owners replacing the stock bolts with ones that have a shank that is a little too long so that when the nut is tightened on the bolt it stops on the shank instead of the sprocket tube. Over time that will allow the sprocket tube to rotate slightly on the axle which can elongate the hole and cause you to have to replace the sprocket tube assembly.

Finally look to make sure all of the sprocket assemblies look the same. If one is bolted through the axle and another is welded on the axle that should be an immediate flag to you that something has been replaced with non-stock parts. It will be up to you to examine the replacement part and ensure that it is up to par and structurally sound. Otherwise you may be replacing the jerry-rigged parts and replacing sprockets can be an expensive repair.

Motor
Before you start any motor check the oil. Make sure it is at the proper level. If the oil is dirty that may be an indicator that the motor wasn't properly maintained and could fail prematurely. If it is clean then you at least know the owner changed it before trying to sell it.

The first obvious indicator regarding the condition of the engine is whether or not it will start and run properly. If it starts up fine and seems to idle at a low and steady RPM then you can rev the motor slightly to see how it reacts. Check to ensure that it is revving properly and coming back to about the same idle relatively quickly.

2-stroke
If the two stroke motor starts easily listen for any misfires or popping. The motor should of course idle smoothly. If the motor is out or will not start and you have a willing seller you can perform a compression test but do not rely solely on compression to determine if the motor is good. While little compression can indicate a worn out motor, one with good compression can still have other problems.

When running, look for white smoke which is indicative of a coolant leak in a water cooled motor or a bluish white smoke which could mean that you are burning oil. That could be from a bad piston rind or valve stem seals. It could also be blow by from oil entering through the air cleaner. If it has black smoke then it is running rich. That could be a partial choked engine from the choke not properly adjusted or the carburetor may need adjusting or cleaned. Black smoke could also be from a dirty air cleaner. Finally while the engine is running listen for any unusual knock or other noises that may be an indication of internal engine wear.

Transmission
With the multiple transmissions produced in the various ATVs manufactured over the past 40+ years it can be hard to give a cover-all statement about them but there are a few things that apply across the board. Whether the ATV is controlled by a steering wheel, handle bars, or laterals you will want to make sure that the movement is the same on the right and left side. If not, that could be as simple as an adjustment to the linkage, band, or puck or as a worst case it could be early signs of something wrong internally.

Have someone move the sticks, steering wheel, or handle bars left to right while you watch the mechanical linkage. Listen for any weird sounds and look for any bindings in the linkage. Make sure that both the right and left side physically look the same and that they do not hit any obstructions. With two identical systems side by side it is easy to see if one side is bent or misaligned. Once you are comfortable with the linkage take the ATV for a spin.

Test the brakes first at a low speed to make sure that the ATV will stop. Then you can get up to speed and try to turn both directions. Make sure that you can turn equally to the left and right. Then stop, put it in reverse and make sure that it can turn equally both directions in reverse too. If it is more difficult to turn one direction compared to the other that could be signs of trouble.

If you have never driven a skid steer ATV before then it is sometimes hard to judge the sounds coming from the transmissions. Since they use braking as a way of turning the transmissions will often make strange noises. T20's will chatter a little when you have them partially engaged. Systems that use pads will sometimes squeal. But if you hear any loud clanks or steady bumping / wobbling coming from the transmission it would be advised to take a closer look and perhaps have someone familiar with those transmissions take a look before you purchase.

Seats
While seats aren't really a big concern since they can cheaply and easily be repaired or replaced just check the wooden base if you can. They are prone to rotting from water damage and can be a pain in the butt (pun intended) if they start to break or disintegrate. If there is a rip, tear or puncture anywhere in the seat material it can let water get to the seat foam where it can stay moist for days accelerating the rotting process. It can also expedite the rusting process on a metal seat frame so be sure to check it for structural stability before you take a seat.

If the ATV has a formed plastic or poly seat make sure that it isn't cracked or missing. Covered foam seats are simple to replace but a formed seat that is no longer made is a little more difficult. There would be nothing worse than having to pay a premium to get a seat on the used market just to complete your ATV.