How to Adjust ATV Chain and How Tight Should It Be?

Knowing how to adjust an ATV chain helps you maintain and operate your ATV at its best. It also saves you a trip to a shop to deal with something easily managed at home. All it takes is some knowledge, focus, and enough time to get the job done.

First, to know how to adjust an ATV chain, you must understand what the chain is and why it’s there. An ATV drive chain looks similar to what you would find on a bicycle. Some modern ATVs don’t have a drive chain, so consult your manual if you can’t find one.

When an ATV engine turns over, the transmission causes a front sprocket to rotate. That turning sprocket pulls the drive chain, which in turn pulls the rear sprocket. That makes the rear axle turn, which spins the wheels and propels the ATV forward.

If you hear a strange, almost crunching noise while rolling an ATV forward in neutral or feel resistance outside of the norm, you might have chain problems. A jerky feeling, or power loss and clicking noises while driving, is a sign that your chain is loose. Of course, if the chain falls off, it’s clearly too loose.

It’s wise to check your chain routinely. This part can stretch and become loose through regular wear and tear. Trying to drive with a chain that is too loose can pull off sprockets, break cases, rip gears out of the motor, and otherwise cause problems.

How to Adjust an ATV Chain

You will need some wrenches or sockets, a measuring tape, and a screwdriver. Check your ATV’s user manual to learn the recommended slack. It is usually one to one and a half inches.

Start by putting your ATV on level ground and shutting off the engine. Have someone sit on the ATV to see what tension the chain is usually under with a rider aboard. Measure from the skid plate or chain guard near the center of your swingarm. Take note of the measurement where the chain rests on its own, then pull up the chain and note the measure at the highest point. The difference between those two points tells you what your slack is. If it’s outside of what the manual says, you will know if it’s too loose or too tight.

Tightening an ATV Chain

To tighten the ATV chain, loosen the bolts on the bearing carrier. Then loosen jam nuts on the adjuster bolt(s). Tighten the adjuster bolt to tighten the chain. Go through the measurement process again, with weight on the ATV. Keep measuring and tightening until you are within the range of the user manual. Once the slack measurement is correct, tighten all of the hardware and jam nuts again.

What if you don’t have adjuster bolts on your ATV? The process is similar, with a few differences. You will still loosen the bolts on the bearing carrier. Then, you will find a hole that allows access between the carrier and sprocket. This is where you will insert a screwdriver or Allen key. Put the Allen key or screwdriver in place, then rotate the rear wheels forward to tighten. The screwdriver or Allen key ensures that the chain adjusts while the bearing carrier is rotated. Again, put weight on the ATV and take measurements. Adjust until it is within the right range. Tighten all of the hardware once that process is complete.

Loosening an ATV Chain

An ATV chain that is too tight can wear out sprockets prematurely. While a loose chain is reasonably obvious, it can be trickier to determine that your chain is too tight. One method is to use your hands. If the chain doesn’t give much when you press down on it, it needs more slack.

You can also use your hands as a preemptive measurement tool before every ride. Stack three fingers on top of one another and place them behind the chain slider. With the chain draped across the top of your index finger, it should be taut overall. Anything looser or tighter calls for adjustment.

Luckily, the process to fix it is the same as tightening, in reverse. Instead of tightening adjuster bolts or rotating the bearing carrier forward, loosen. Measure for slack as you would when tightening the chain.

If the chain is still too tight and you cannot loosen it further by adjuster bolts, you may need to lengthen the chain. That requires taking the chain apart and adding a master link to it. You can also shorten a chain if need be by removing portions and using a master link to put it back together.