If you’ve just read our article on the ins and outs of motorcycle exhausts, you may be keen to go and buy a replacement system for your bike. It’s not a cheap modification by any means but in relation to the horsepower gains and weight savings it produces, it’s good value. Some might be scared of installing the exhaust themselves given that it connects to your engine, but fear not. This is one of the easier upgrades you can do yourself.
While the specifics of removing your old exhaust and installing a new one will differ from bike to bike, the overall process remains similar. The time it takes will vary greatly depending on how many cylinders your bike has. A thumper will be nice and quick while a four cylinder will take a little bit longer. You’ll almost definitely need to remove fairings from both sides of the bike to gain access to all the places you need.
Tools we’d recommend you have at your disposal are:
- Breaker bar, to loosen any bolts attaching the old exhaust to your bike
- Ratchet wrench for removing said bolts
- Torque wrench to tighten the bolts when attaching the new exhaust system
- Thread lock to help secure bolts in place
- Muffler and exhaust sealant to ensure no air leaks from your new pipes
When removing your old exhaust, start at the muffler. By detaching it from your bike and removing it from the exhaust, your removing the heaviest part of the exhaust system. This will ensure you don’t bend the header pipes which connect to the exhaust ports. You’ll need to use your breaker bar here to loosen any bolts.
Once the muffler is removed, loosen any bolts that are keeping the remaining exhaust pipes connected to your bike – but keep it attached for the time being. Remove the bolts that are holding the manifold in place next to the exhaust ports – again your breaker bar will come in handy here.
Hold the exhaust system and remove the last bolt(s) holding it in place. Push the exhaust forward so that the header pipes exit the exhaust ports smoothly. You’re halfway there! If you’re not going to immediately install your new exhaust, cover up the exhaust ports so dust and other particles can’t get in – masking tape will do fine.
Now’s the time to start installing. We’ve gone with a Tyga Performance full system. We’ll be elaborating on our choice in our next Ninja 300 Project Bike update, suffice to say that the Tyga system provides more horsepower gains compared to other systems at nearly half the price. We like that.
It’s probably a good idea to do a quick practice run of putting your exhaust together before attaching it to the bike. One thing to keep in mind is the headers. Specific header pipes will need to go into specific ports – so make sure that you know which is which (they’ll be labelled). If you’ve got a four cylinder bike, you won’t want to have to put that puzzle together without guidance.
One thing to consider is putting new crusher gaskets in your manifolds. These little gaskets help ensure a seal between your exhaust ports and the manifold, preventing any air loss. They’re pretty cheap and ensure all the money you’ve spent on your new exhaust isn’t wasted by a silly air leak.
For installation, we’ll go in the reverse order of removal. Place the manifolds onto the ports. At this stage, tighten the bolts with your hand only as you’ll want the header pipes to be able to move a bit when attaching them to remainder of the exhaust pipe.
Attach the exhaust pipe to your bike, again only hand tighten at this stage. Make sure everything lines up and before connecting, place a good amount of muffler/exhaust sealant onto the outside of the pipe that will go inside the other pipe. That generally means putting the sealant onto the outside of the header pipe and connecting it to the exhaust pipe. Put it about a quarter of an inch thick and about an inch wide – starting about a quarter of an inch from the edge of the pipe.
Connect the two pipes and then wipe away any residual sealant on your pipes. Now you can tighten both the bolts on the manifold and on the frame. In an ideal world, you’d use your torque wrench to tighten these bolts to the torque values specified by your motorcycle manufacturer. Unfortunately because of the confined spaces, our torque wrench wouldn’t fit so instead we used thread lock on the nuts and stopped tightening as soon as we felt resistance.
Depending on the fit of your muffler, you may or may not need to put muffler sealant on the pipes there too. Generally the fit here is much better than where the headers and the tail pipe connect. Attach the muffler to your bike (usually it bolts onto the passenger foot peg bracket) and you’re all good.
Wait 30 minutes for the muffler sealant to dry before starting the bike. Once the bike is running, place your hand over the connections to feel for any air leaking out. Just be careful as the pipes will become extremely hot within a few seconds of the engine running.
If you feel any air leaks from around the manifolds, it almost always means you need to install new crusher gaskets. For air leaks between the pipe connections, try and smear some more muffler sealant into any gaps (but wait until the pipes have cooled before doing so).
Keep in mind also that you should be very cautious about riding your bike with a new exhaust without having the fuel system retuned. Your bike’s engine is now getting a lot more air into it but with the same amount of fuel as before. That means your air/fuel ratio isn’t correct which causes your engine to running lean. That might just mean your bike runs a little off, but it can also mean that it overheats to the point of being destroyed.
To correct that, you’ll need a jet kit for a carburetted bike (and a dyno tune) or a fuel controller for an EFI bike (like a Power Commander) plus either a trip to the dyno or an additional module that automatically corrects the air/fuel ratio. Those automatic systems use an O2 sensor that goes into the exhaust – hopefully you bought one with the requisite opening for such a sensor. If not, you’re going to have to get someone to cut a hole into your shiny new exhaust for you.