Dirt bike chains are often times looked passed and not checked by most riders. This is not only dangerous but could also cause abnormal wear and tear on the sprockets and chain of the bike. By following these steps, one will be able to properly adjust his or her chain on their dirt bike to the proper adjustment. Note: All pictures within this report are my own and have been taken in order to help describe each step in the process.

Supplies

12mm opened end wrench
10mm opened end wrench
Crescent wrench or 22mm 1/2" drive socket + ratchet (for axel nut)
If your bike is a Husqvarna or KTM then it will take 13mm opened wrench and 10mm opened wrench along with crescent

Step 1: Get the Bike Off the Ground

Grab a dirt bike center stand and place it where the ground is level. Then place the bike on the stand and center it up so that the rear wheel is off the ground. If you do not have a center stand you can leave the bike on the ground when making the adjustment. At this time, you should also gather all of the required tools.

Step 2: Loosen the Axel Nut on the Back-wheel

Loosen the axel nut on the back wheel. To do this you will take your crescent wrench or 22mm ratchet and socket and place it on the nut. Note:If you are using a crescent wrench make sure to adjust it so that it is tight on the nut and will not slip off and begin to strip out the head of the nut.

Step 3: Loosen Locking Nuts

Loosen the nuts that are located on the adjuster bolts. These nuts are used to the lock the adjusters in black so that they cannot turn in or out. These nuts are 12mm on Japanese made bikes and generally 13mm on KTMs and Husqvarnas. They are on both sides of the bike because there is adjusters on both sides so that the rear wheel will stay straight. If you start by loosening the one on the right side, you will be pulling the wrench up in order to loosen the nut (counter-clockwise). Once moving on to the left side you will notice that you must push the wrench down in order to turn it counter clockwise. At this time, you should also make sure that the rear wheel is straight by counting the dashes on each side of the swing-arm and seeing how far back the adjuster block is on each side. The dashes are used as an indicator to show you how far back each side of the axel is in the swing-arm and make it easier to equal them up with one another.

Step 4: Adjusting the Chain

Tighten up the chain by turning the adjuster bolts counter clockwise and drawing them out of the swingarm. Make sure that you turn each adjuster the same amount. By turning the bolts clockwise and drawing the bolts in it will allow the wheel to slide forward and loosen the chain. Adjust the rear wheel until there is about two inches of slack in the chain when the rear wheel is off the ground. If your bike is still just sitting on the ground, adjust the chain until there is roughly ¾ - 1 inch of travel in it when you are sitting on the bike. I most often times check my chain by using my fingers to check the slack between the chain and the swingarm. Before moving on to the next step set the bike down and check the chain for proper adjustment of ¾ - 1 inch of travel.

Step 5: Retighten Locking Nuts

Once the chain is properly adjusted make sure both adjusters are equal and retighten the adjuster lock nuts by turning them clockwise with the 12mm opened end wrench. You can also slightly snug the adjust bolts up, do not tighten them much from here at all.

Step 6: Retighten Axel Nut

The last and final step is to retighten the axel nut (turn clockwise) using your crescent wrench or 22mm socket. Make sure not to over tighten the nut and strip it but do make sure it is not going to loosen up by tightening to about 40-45-foot pounds of torque.