The Yamaha YFZ450 and the YFZ450R are probably the best ATVs around. They’re fast, powerful, and lightweight, but they can be even better with an aftermarket exhaust system
If you want to hear your YFZ450 roar freely, then this article is for you. We’ve scoured the internet and found the four best exhausts for YFZ450 and YFZ450R.
The 4 Best Exhausts for YFZ450 & YFZ450R
  | 1. Big Gun Evo Race |
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  | 2. Big Gun EVO R |
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  | 3. Sparks Racing X6 Full Exhaust |
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  | 4. Yoshimura RS-2 |
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1. Big Gun Evo Race Slip-On for 09-19 YFZ450R
Big Gun exhausts are very popular and for good reason. They’re well made, lightweight, loud, and very inexpensive.
Proudly made in the USA, the Big Gun Evo Race slip-on will give your YFZ450R 4-8 more horsepower, better throttle response, and noticeably more torque throughout the whole RPM range. Because of that, the Evo Race is the perfect choice if you’re looking for maximum power gains and don’t mind having a loud exhaust.
To get a 4-8 HP gain with the Evo Race slip-on, it’s always recommended to rejet your carb in order to richen the mixture and compensate for higher exhaust flow.
With that said, the Evo Race slip-on is really loud, but that can be reduced to 96 dBs with a Vortex insert, which is sold separately.
Weighing in at just 8.15 lbs, the Evo Race slip-on is significantly lighter than the stock muffler and just as durable. It’s made from .049 stainless steel tubing and will easily fit 09-19 Yamaha YFZ450 and 10-11 YFZ450X.
2. Big Gun EVO R for 04-09/12-13 YFZ450
But what about the YFZ450? Big Gun exhausts have got you covered again!
The EVO R is specifically designed for the 04-09 and 12-13 year Yamaha YFZ450s and promises to add 4-8 HP to your ATV. Not only that, but it noticeably improves throttle response and torque, due to greater exhaust gas velocity. For best results, always rejet your carb to accommodate the increase in the exhaust flow.
The EVO R is much lighter than the stock and is made from 304 stainless steel for durability and rust resistance.
Now, as far as sound goes – the Big Gun EVO R is loud and gives the YFZ450 a powerful and throaty sound. Perfect if you want more horsepower and more sound.
3. Sparks Racing X6 Full Exhaust for 04-13 YFZ450
If you want to squeeze the absolute maximum out of your Yamaha YFZ450 and make it sound amazing, then the Sparks Racing X6 Full Exhaust should be no. 1 on your shopping list.
Slip-on mufflers are great and will increase HP, but a full system will always be superior. The guys at Sparks Racing completely redesigned the exhaust system for the YFZ450 to squeeze maximum power out of the engine.
By completely redesigning the stock exhaust system, they bypassed the restrictive stock head pipe and fine-tuned the exhaust system using a dyno. The result is a full exhaust system that provides huge power gain and significantly better top-end performance. Because of that, the Sparks Racing X6 is probably the best exhaust for YFZ450.
With that said, the X6 is loud – around 110 dB.
As for the build quality, the X6 Full Exhaust System is outstanding. The exhaust system is made from lightweight 304 stainless steel and is beautifully TIG welded.
4. Yoshimura RS-2 Slip-On for 09-13 YFZ450R
Last but not least – the Yoshimura RS-2. This slip-on is pretty pricey, but it hits the sweet spot as far as sound goes.
The RS-2 was based on their previous race-proven TRC line exhausts and is engineered for increased power and delivery. Inside the slip-on exhaust, there is a diamond-shaped sleeve, which provides increased volume. However, the RS-2 is more on the quieter side due to its large core and it peaks at 96 dBs with the spark arrestor, which comes included with the slip-on.
The RS-2 is by far the lightest one on our list at just 6 pounds, and there’s a whole range of repack kits and DB killers available from Yoshimura.
How To Buy The Best Exhaust for YFZ450
Before we let you go, here are a few things that you should consider and keep in mind while shopping for an exhaust for your Yamaha YFZ450 or YFZ450R.
Full System vs Slip-On
The first and most important decision that you will have to make while exhaust shopping will be full system vs slip-on.
A slip-on is the most popular choice and for good reason. They’re extremely easy to install (as the name suggests), inexpensive, loud, and will add quite a significant amount of HP to your YFZ450 or the YFZ450R.
On the other hand, a full exhaust system costs a lot more, but you also get a lot more out of it. Since a full system replaces the stock piping, it will always provide more exhaust velocity and ultimately more power and sound.
In the end, it all comes down to how much you’re willing to spend. If you’re tight on a budget – go for the slip-on. They usually cost just a few hundred bucks and will still add at least 4 HP to your YFZ450 and make it sound mean.
But if you don’t mind spending more, then getting a full system is a no-brainer. Full systems redesign the stock piping and provide the maximum amount of exhaust velocity possible. They’re always dyno tuned and tested by professional riders at the track, before being shipped for sale.
Rejet Your YFZ450 After Installing a New Exhaust
Both YFZ450 and the YFZ450R run on the leaner side from the factory, and in order to make the most out of your new exhaust – you must rejet your ATV to richen the mixture.
Even a new slip-on will provide the YFZ more exhaust velocity and since the engine will suck in more air, you have to compensate for that by rejeting your carb and richening the mixture. Not only will this protect your engine from overheating due to an overly lean mixture, but it will also add a lot more power since you can spray more fuel into the combustion chamber.
YFZ450 Exhaust FAQ
Does aftermarket exhaust add power?
Yes, an aftermarket ATV exhaust will add at least 4 HP. A full system, on the other hand, will add 10 HP and even more in some cases.
How hot does a YFZ 450 Exhaust get?
The exhaust on most ATVs, including the YFZ450, peaks at 1300°F at wide-open throttle.
Jake is the site’s primary contributor.
Motorcycles and automotive repair have been a big part of his family for generations, therefore it’s only natural that he decided to become a heavy-duty diesel tech.
Outside of work, you’ll find Jake restoring and riding rare street bikes and ATVs.