Motorcycle Exhaust Installation
Instruction manuals. People who refuse to read them look super cool in the garage. They look less cool beside the Trans-Canada Highway, searching for the exact spot where their slip-on slipped off.
You know what to do. And don’t worry, we won’t tell anyone.
So once you've spent a solid 15 minutes "not" reading the instruction manual, we can go ahead and get started. The general procedure is outlined below. I won’t bother telling you exactly which nuts and bolts to fiddle with, because the instruction manual will give the specifics for your particular system. And you “didn't” spend 15 minutes reading through it beforehand, of course…
Before You Start
Take the exhaust out of the box and inspect it. If there are damaged parts or missing pieces, you can send it back to us for a full refund. But once you start fiddling with the installation, we won’t know if the dings are from you or the manufacturer.
Next, get your equipment ready. The instruction manual (which you didn't read) should indicate what you need. There are a couple extras it might not mention. For example, many full exhaust systems do not supply header gaskets. And since these are easily damaged while removing the stock system, we recommend grabbing some new gaskets before you begin. Also, many riders like to use high-temperature silicone sealant on the pipe connection points. This isn't always necessary, but it’s cheap insurance against exhaust leaks.
Removing the Old Exhaust
In some cases, it’s as easy as loosening a few bolts or clamps and pulling it off. With other motorcycles, you may need to remove various body parts to get at the exhaust.
As you go about this, pay attention to what you need to reuse. Most installations will employ some of the old clamps and hardware. Likewise, sensors and other electronic components are often reincorporated into the new exhaust. As we mentioned above, header gaskets are normally impractical to reuse. We recommend buying some new ones beforehand.
Whatever you don’t reuse should be carefully stored. I can give five good reasons for this.
- You might break something down the road, so having a spare exhaust will come in handy.
- In some places, a mandatory re-inspection can follow any noise or emissions violation. Your stock exhaust will probably be useful in passing it.
- Motorcyclists are pretty divided on the loud exhaust issue. So if you want to sell your bike in the future, having both types will open doors for more buyers.
- Some race courses require all track-day participants to run a stock exhaust.
- Vehicles being imported are normally tested for noise and emissions standards. So if you ever move or sell your bike abroad, a stock exhaust is like the motorcycle’s passport.
Installing the New Exhaust
The pipes should slide together without any grease. Sometimes there are metal burrs on the joints, which are remnants from the manufacturing process. If this is the case, carefully file off the pokey bits. Once you fit the pieces together, they are normally secured with springs.
As mentioned already, some riders will use high-temperature silicone sealant to ensure an airtight fit. This can be done at your discretion, but make sure to allow the entire setting time before starting your bike. Otherwise, the heated pipes will liquefy the silicone.
Now, remember to replace the header gaskets if applicable. Then, loosely bolt or clamp the new exhaust onto your bike. Study the system, and check to make sure the orientation won’t cause any problems. Does the exhaust contact the fenders, or anything else that could be damaged by heat? Will it eject fumes onto the passenger’s foot? If it’s a high mount exhaust, you may have to remove the passenger foot pegs. Other types will allow you to retain them.
If everything looks good, you can tighten up the bolts and clamps. It’s probably worth using a torque wrench for this. If you have a delicate exhaust, the owner’s manual will say how hard to tighten things. Go above this, and you risk cracking those shiny new pipes.
Now, modern bikes might have emission control sensors or exhaust management cables (the latter is used to change the diameter of a stock exhaust to muffle noise at various RPMs). You might be able to reattach these systems to the new exhaust. More commonly, however, the devices are simply disabled. Sometimes this involves going into the black box to cut a wire. Other times, you just attach a servo eliminator or a sensor eliminator to the wire's end. Exhaust management cables are normally left unattached. You can use zip ties to secure the cables out of the way. If you fail to disable these systems, your bike will still run properly. However, your dashboard warning lights will light up like a Christmas tree.
Once your exhaust system is installed, you can think about any air-fuel adjustments that might be required.
Testing the New Exhaust
Before you start the bike, wipe down the exhaust system with a clean rag. You probably left a bunch of greasy fingerprints on there, and they can permanently discolor the exhaust once it heats up.
After a good ride, you should check the bolts and brackets. It’s fairly common for them to vibrate loose on the first couple runs. If this is the case, just snug them up again with a torque wrench.
It's also common for new exhausts to emit smoke while the manufacturing oils burn off. The problem shouldn't persist beyond the first few rides.
There are a few other things you might notice: popping sounds when decelerating, abnormal amounts of backfires, strange whooshing noises or black discolorations on your leg and bodywork. All of these things can indicate a leaky exhaust. If this applies to you, find the leak by putting a board against the muffler opening and listening along the length of the pipe. If you can’t hear it, burning some incense smoke around your muffler will reveal wayward air streams. Almost certainly, the leak is at one of the joints you just put together.
When you find the leak, check first to see if the clamps, bolts or springs are tight enough. If the leak is at the header, your gaskets might be bad. If it’s somewhere along the length of the exhaust pipe, you may need some high-temperature silicone to make an air-tight seal.