Every motorcycle has components that must be replaced due to normal wear and tear. Dirt bikes, however, are exposed to harsh conditions that can quickly deteriorate even the most heavy-duty components. The drive chain falls into this category. Over time, these chains can stretch beyond their serviceable life and even snap in extreme cases, leaving the rider stranded. Replacing a worn chain may seem daunting, but with the proper tools and a little preparation, the job can be done quickly and easily.
Removing the Old Chain
1) Remove the engine’s sprocket cover by removing the mounting bolts with the appropriately-sized Allen key or socket.
2) Loosen the rear wheel chain adjusters and axle nut, then slide the rear wheel forward to release tension on the chain.
3) Locate and remove the old master link from the chain, using a chain breaker tool. Additionally, you may grind off the side plate pins on thicker chains (No. 520 or larger) to help prevent damage to the chain breaker tool.
4) Pull the old chain off of the front sprocket and discard.
Installing the New Chain
5) Determine how many chain links are required by your dirt bike. This information is found in your owner’s manual or service manual. However, most newer motorcycles also list the chain information on the frame or swing arm.
6) Cut the new chain to the required length by breaking off the first excess link, using a chain breaker tool.
7) Place the new chain on the front sprocket and pull it through to the rear sprocket. Place the master link onto the open ends of chain to join them. If you are installing an O-ring type chain, several O-rings and lubricant will be included with the master link. Slide the O-rings onto the new link, and coat them liberally with lubricant before sliding it onto the rear of the chain. Install the remaining O-rings onto the pins, coating them with lubricant before sliding the link’s side plate into place.
8) Press the pins into the link, using a chain press; the pin should be rounded off or mushroom-shaped.
9) Slide the rear wheel back and adjust the chain adjusters to tighten the chain. Chain slack should not exceed a finger’s width of travel in either direction. However, refer to your owner’s manual or service manual for the manufacturer’s recommendation.
10) Check the rear wheel’s alignment, tightening the axle bolt once the rear wheel is straight. Adjust the chain adjusters if required.
11) Re-install the front sprocket cover and tighten the mounting bolts.
12) Lubricate the chain with an off-road specific chain oil.
* If the chain pin doesn’t break free after a small amount of tension, back the breaker tool’s tip out and check your alignment.
* If you are uncomfortable performing this task, you should have the work done by a qualified technician.
* Do not use air or power tools in conjunction with the chain press or breaker tool. Chain tools are designed to by applied by hand and can be damaged by excessive force.
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