How To: Install a Dirt Bike Exhaust System

How To: Install a Dirt Bike Exhaust System main image

Installing a new exhaust system on your dirt bike is generally one of the more simple tasks, although there are few key steps to take along the way to ensure it bolts on smoothly.

Our Honda CRF450R project bike was already an absolute machine, but we sat back and thought to ourselves, how can we make this thing even more of a beast than it already is? The answer - a FMF Anodized Titanium Factory 4.1 Dual Exhaust System

An absolute beauty of a part all on its own, we knew that this thing would take our CRF450R to the next level and beyond, plus make it look even more beautiful than it already was. We decided to film the installation process along the way, and we're proud to bring you this easy step-by-step guide on installing a new motocross exhaust system on your prized 4-stroke machine. Check out the video below.

How to install a dirt bike exhaust:

Step 1: The first step to installing a new exhaust system on your dirt bike is to remove the old exhaust. To do this the only dirt bike tools you should need are some T-Bars and a set of pliers if your exhaust has any springs. We used an 8, 10, 12mm T-bar set for our Honda CRF450R model, although it's important to note that some bikes will vary, with most KTM's and Husqvarna's also needing a 6mm T-bar too.

Start by taking your pliers and removing any exhaust springs by clamping the end of the spring firmly and stretching the spring until it can be unlatched. Be careful not to slip with the pliers as these can be a little tough! Once the springs are off you can move onto the exhaust silencer/muffler. You will need to remove the side panel first to expose all of the bolts. Some exhausts will be a three piece system and many others will be a 2 piece. 

Step 2: The next step is to use your T-Bars to remove all of the bolts from the exhaust header/expansion chamber. Some exhaust systems have a bracket which has a second bolt onto the frame. This allows for a rubber spacer and reduces vibration. This also helps with lining up the pipe correctly but for now just loosen the bolt which is directly fixed to the pipe.

Once all of the bolts are out of the header/expansion chamber, gently remove the pipe from the bike. Two stroke machines usually have rubber O’ring seals which help seal the pipe against the engine. You may need to replace these on the new pipe, or at least swap them onto the new pipe, make sure you add some grease to the rubber help keep the seals in good condition.

Step 3: When the pipe is removed start by adding the header pipe first. The trick is to put the whole exhaust on with all of the bolts left loose. This will help you manipulate the pipe and line it up easily. Some exhausts can be a little tight and will need to be twisted and pushed into place before tightening all of the bolts off.

Step 4: Work your way from the front to the back of the exhaust pipe until it is on and all of the bolts are done up with your hands. Double-check the entire exhaust is lined up straight and in the correct place and from there you can begin tightening up all of the bolts. Start from the rear of the bike this time and work your way forward. Once all of the bolts are tightened you can go through and replace all of the tensioning springs also. Replace the plastics on the bike and you are ready to roll!

Fuel-injected bikes will adjust their mapping automatically once you have added a performance pipe so suit. But there will be more instructions for this included when you purchase any particular pipe as some brands may vary in information.

For dirt bikes with a carburetor, you may need to re-jet your bike to get the fuel/air mixtures right. Consult a mechanic or your owner’s manual if you are unsure as if your bike isn’t jetted correctly it can severely effect your bikes performance or actually cause engine damage.

Visit the MXstore Help Center if you are having trouble getting your exhaust system to fit.

Explore the largest Australian range of dirt bike exhaust systems at MXstore:

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