Trying to find the best 2 stroke dirt bike exhaust but not sure where to start? Upgrading the exhaust is a popular dirt bike mod, so whether you’re riding on the trails, racing motocross, or enduro riding, there is an option for you, but it may not be what you think.
In this article, you’re going to learn what exactly a 2 stroke exhaust pipe and silencer do, why you may or may not want to upgrade to an aftermarket system, and how to choose the right one based on your specific needs and budget.
What is a 2 stroke exhaust called?
A 2 stroke exhaust can be called a few different things, but the technical term for the pipe is an “expansion chamber”. It may also be called a “tuned pipe” because it’s tuned specifically for that engine to make the most efficient torque and horsepower.
Even the best 2 stroke dirt bikes can be improved with a pipe upgrade depending on where you want the most power.
Why do 2 strokes have a big exhaust?
2 stroke engines have an “expansion chamber” exhaust pipe because they are a part of the “tuning” to make better power. The size, shape, and length of the big expansion part of the exhaust determine what kind of power curve the engine will have.
For example, a 125cc 2 stroke has a smaller and shorter expansion chamber, giving it more top-end power. If it had a larger and/or longer expansion pipe, it would have a smoother and more torquey-er power curve, but with much less top-end power.
There are some similarities when comparing it to a 4-stroke exhaust, but the way each engine works requires a different type of pipe to pull out the exhaust gases quicker and more efficiently.
2 stroke pipe vs silencer - what’s the difference?
The pipe is the big expansion chamber that comes out of the engine and the silencer is the tail pipe or muffler where the exhaust comes out on the rear of the dirt bike.
They both are used to tune the power, but the main difference is that the pipe makes a bigger difference to the power curve while the silencer controls the exhaust sound that it makes (tone and noise level)
How to make your 2 stroke dirt bike louder
The easiest way to make your 2 stroke dirt bike louder is by removing the silencer, but why would you want to do that when there are so many drawbacks? Sure, you get more noise, but the cons generally outweigh the pros of a louder dirt bike, which I’ll cover in just a moment.
If you have a stock silencer on your 2 stroke motocross or enduro bike, then simply switching to an aftermarket shorty silencer will give you more noise. Since there’s less silencer length on a “shorty” silencer, there’s less “packing” to reduce the exhaust noise.
Why a quieter 2 stroke exhaust might be better
I’m not against having a loud 2 stroke dirt bike exhaust in certain cases, but for the most part, they’re not necessary.
Here are several reasons why it’s better to have a quieter exhaust on your 2 stroke dirt bike:
Not as annoying to others
As much as you like hearing a loud and snappy exhaust sound, most others don’t care for it - especially people that don’t like dirt bikes to begin with. So, if you’re riding near a neighborhood or around many other people, it’s a little less rude to have a quieter exhaust.
If you only care about yourself and what you want, then you can leave my website right now - you’re the reason why people hate dirt bikers.
Potentially not as much power
If you want the best 2 stroke dirt bike exhaust simply to make it louder, then you may be surprised when your bike has LESS power. You see, the stock exhaust system is actually really good these days because the manufacturer tunes it for the best overall power.
So, when you install a louder exhaust WITHOUT properly tuning the jetting (or EFI), then it’s probably going to make less power and not run as well.
Less tiring
More noise may sound cool, but it’s actually more tiring while you’re riding - especially if you don’t wear earplugs. When you have a quieter exhaust, it’s easier to relax and ride longer because your eardrums aren’t constantly blasted with 100+ decibels.
Less chance of getting shut down
While it’s not the only reason, the noise dirt bikes make is one reason why some of the best riding places are getting shut down all over the country. Whether it’s motocross tracks, riding parks, or state trails, it only takes ONE person with a voice/money to complain and get it all shut down these days.
Do us all a favor and ride under the legal decibel limit at your track, park, or trail. This is one reason why so many people are anxious to buy an electric dirt bike - whether you like them or not!
Not as intimidating to little kids
If you’re riding with little kids, then you’ll find out how they are much more susceptible to loud noises. If your 2 stroke dirt bike exhaust is extra loud, you may scare or intimidate them - especially if they’re nervous about riding a dirt bike in the first place.
Do 2 strokes like high RPM?
“Back in the old days” of the 80s and 90s, virtually every 2 stroke dirt bike liked to be ridden at high RPM. Most people thought that having the “most horsepower” was the only way to be faster than the next guy, so that’s why 2 strokes used to be tuned like a lightswitch - all top end horsepower at high RPM with little to no low-end torque.
What we found out is that having a “snappy” powerband like this makes it hard to ride, especially when the terrain and conditions are slippery. This is why many modern 2 stroke enduro bikes have more low-end and midrange torque so that you don’t have to constantly rev them high.
Not only are they easier to ride, but it’s less exhausting and cheaper to maintain because you can ride just as fast and with more control at a lower RPM.
Do 2 strokes make more torque?
For the same size engine displacement, a 2 stroke will generally make more torque and horsepower. For example, a 250F enduro bike makes about 18 ft. lbs of torque while a 250 2 stroke enduro bike makes about 25 ft. lbs of torque.
The main difference is that a modern 4 stroke dirt bike engine will make the same power over a bigger RPM range, allowing you to ride faster because you can stay in the same gear longer without needing to shift.
How does a powerband work on a 2 stroke?
The “powerband” is simply the RPM range when a 2 stroke engine makes the most power. Back in the 90s when 2 stroke dirt bikes had “snappy” or “pipey” powerbands, they would be slow to rev up because they didn’t have much low-end torque.
But once the RPM reached a certain RPM (usually around 6-7k RPM), there would be a huge “burst of power” because the horsepower would greatly increase. This gives you that distinct feeling of “hitting the powerband” or getting “on the pipe”.
Do you need a spark arrestor?
If you are riding on a state trail in the United States of America, then you’ll need a USFS-approved spark arrestor to be legal. Most 2 stroke silencers do not have one from the factory.
A spark arrestor is simply a screen or system that restricts any spark or backfire from going out of the exhaust so that it doesn’t start anything on fire. While you can insert a screen on the end cap of your 2 stroke dirt bike silencer, it’s technically not legal without the USFS-approved stamping on the exterior of the silencer/muffler.
Best 2 stroke dirt bike exhaust brands
There are quite a few companies that make aftermarket exhaust systems for 2 stroke dirt bikes these days, ranging from inexpensive to less affordable. Choosing the best 2 stroke dirt bike exhaust mainly comes down to your specific needs and budget.
If you’re happy with your stock exhaust system, then there’s no need to upgrade - stock pipe and silencers generally make the best overall power.
But, if you want the shift the power around, have that “factory look”, reduce weight, or change the exhaust tone/sound, then changing to an aftermarket exhaust is right for you.
Here are the top 2 stoke dirt bike exhaust brands to choose from:
FMF
“Flying Machine Factory” (FMF) has been around since 1973. They’re the most well-known 2 stroke exhaust brand because they make the highest quality pipes and silencers for the most affordable prices.
There are a few choices when it comes to pipe and silencer options:
Fatty pipe (Gold Series)
The “gold standard” for best 2 stroke dirt bike pipe upgrades is the FMF fatty pipe (Amazon). It makes slightly more power overall than stock, with a crisper throttle response, and a durable and shiny nickel-plated finish, all at a fairly affordable price.
“Factory” Fatty
If you don’t mind doing some routine maintenance to keep its look, the “Factory” FMF Fatty pipe (Amazon) gives you the look of a factory racer bike with its raw metal finish that turns blue. It makes slightly more midrange and top-end power and is lighter due to its thinner gauge steel and no plating.
It will rust easily if you don’t regularly clean it - especially if you live in a high-humidity climate.
Gnarly
Worried about getting dents while trail riding? The FMF Gnarly pipe (Amazon) is more durable and slightly quieter due to its thicker gauge steel - plus you get more low-end and midrange torque, making it easier and less exhausting to ride off-road.
Powercore 2 silencer (titanium/standard)
For more power and better (more) exhaust sound, the Powercore 2 silencer (Amazon) flows better than most stock silencers. This gives you slightly more potential power when jetted properly and a crisper feeling and sounding 2 stroke dirt bike.
Shorty silencer
For even more throttle response and low-end torque, the FMF Shorty silencer (Amazon) is your best choice. This is because its shorter length makes it tuned for lower RPM power, which also reduces weight, but makes it noticeably louder (the loudest silencer option).
Turbinecore 2 spark arrestor
If you need a USFS-approved spark arrestor, then the FMF Turbinecore 2 (Amazon) is the most popular option due to its “turbine” design that doesn’t need a screen on the end cap that can clog up and cause major problems.
It’s the quietest 2 stroke dirt bike silencer option, so if you combine the TC2 and Gnarly pipe (MotoSport), then you’ll have the quietest exhaust system that the aftermarket offers.
Pro Circuit
Mitch Payton is famously known for his “Pro Circuit” race pipes that he started using in 1978 and quickly gained popularity through seeing results on the motocross track. His company has been making 2 stroke exhaust pipes and silencers since then, along with many other dirt bike performance upgrades and parts, as well as many other machines.
Here are the best Pro Circuit 2 stroke exhaust pipes & silencers:
“Works” pipe
PC is well known for its “Works” pipe (Amazon) that gives your 2 stroke dirt bike that “works look” while giving you better power throughout the RPM range. If you don’t mind regular cleaning and oiling of the bare metal finish, this is a good pipe option.
Platinum pipe
For the same type of performance gains with less maintenance, the popular Platinum pipe (Amazon) is your best pipe option from Pro Circuit. The nickel-plated finish requires very little maintenance and won’t dent as easily from roost, rocks, or crashes.
Platinum 2 pipe
If you’re a trail rider or hard enduro rider, then you’ll want to consider the PC Platinum 2 pipe (Amazon). It’s stronger due to its thicker gauge steel, and you’ll get better low-end and midrange torque, as well as better throttle response at low RPM, which is where most of us need it for off-road riding.
Factory R304 silencer
For more power, throttle response, and better (more) sound, the Pro Circuit R 304 silencer (Amazon) is a popular option if you don’t need a spark arrestor. You’ll get better power and less compared to stock.
R 304 Shorty silencer
For even more low-end torque and throttle response, the R 304 Shorty silencer (Amazon) is the best option. It works well for riding on tight tracks or slippery conditions where traction is even more important.
Nature Friendly spark arrestor
If you want to legally ride on trails and don’t need the quietest silencer, the PC “Nature Friendly” spark arrestor (MotoSport) is your best exhaust choice. It’s less likely to clog due to oil and unburnt fuel and you shouldn’t notice any power loss over a stock silencer.
Type 296 Spark arrestor
For legal trail riding on state trails or just less noise without losing much power, the PC Type 296 spark arrestor (Amazon) is your best option. It’s similar to the Nature Friendly silencer but it’s longer and therefore reduces the decibel rating to below 96 dB on most models.
Bills Pipes
Bills pipes is a much smaller 2 stroke exhaust company run by Bill Cervara from California. They make custom pipes for most 2 stroke dirt bikes, but availability is not as good as FMF or PC.
Scalvini
Scalvini pipes are manufactured in Italy - they’re designed and tested by Gianluigi Scalvini for each bike.
Factory Works pipe
If you want the trickest-looking pipe, the Scalvini Factory Works pipe (Motosport) delivers with its handmade “cone pipe” design. You get that distinct look of the colorful welds, but you also get better performance from mid to top end. Just remember to oil it after washing or else it will rust quickly.
Race pipe (Stamped)
For a slightly less expensive 2 stroke pipe, Scalvini offers the Race Stamped pipe (Motosport) which is supposed to give you the same performance gains as the Works pipe at a lower cost due to how its made and looks. It’s still a bare metal finish, so you’ll have to keep it oiled to prevent rusting.
Factory silencer (Alum/Carbon)
To get the complete exhaust system upgrade, you can choose Scalvini’s Factory silencer in Aluminum or full carbon (Motosport). The Aluminum body has a carbon end cap and weighs slightly more but is more affordable and still performs better than stock.
Factory Shorty silencer
For less weight and more low-end throttle response and torque, you’ll want the Scalvini Factory Shorty silencer (Motosport). It’s noticeably louder, so keep that in mind if you’re riding in a noise-conscience area.
Lexx
The Lexx Duraflow pipe (Amazon) is a Chinese-made 2-stroke pipe. Will it give you the same performance as a name brand exhaust pipe? Not quite, but it’s pretty close to stock, according to Jimmy Lewis, so it’s a good choice if you’re looking for a cheap replacement pipe for your KTM, Husqvarna or Gas Gas 2 stroke enduro bike.
DEP
DEP offers handmade pipes from Great Britain for most 2 stroke dirt bikes. They offer Nickel plated, unplated “Works” style pipes, a “Rev” pipe for top-end, a “Torque” pipe for low-end, as well as 3 different silencer options.
Bud Racing (HGS)
Bud Racing is a company out of California that develops 2 stroke exhaust systems and then teams up with HGS to make and sell them. They offer a Factory style pipe, as well as a few silencer options for most 2 stroke dirt bikes.
Best 2 stroke dirt bike exhaust for motocross racing
The best pipe really comes down to your personal preference - how do you want your 2 stroke dirt bike power to come on? Smooth, snappy, more low-end, more top-end & over-rev?
For motocross, most people either prefer better power throughout the RPM range or more midrange and top end power with lots of over rev (so it doesn’t fall flat at high RPM).
These are the best 2 stroke dirt bike pipes for MX racing:
- FMF Fatty
- FMF “Factory” Fatty
- Pro Circuit Platinum
- Pro Circuit “Works”
- Scalvini Works
- Scalvini Race Stamped
- DEP Works
- DEP Rev
Best 2 stroke racing silencer for overall power increase:
- FMF Powercore 2
- FMF Titanium Powercore 2.1
- Pro Circuit R 304
- Scalvini Factory
- DEP MX silencer
Best 2 stroke racing silencer for low-end torque:
Horsepower gain vs percentage gain
A common mistake is just looking at the horsepower number gained when upgrading to an aftermarket pipe or silencer on a 2 stroke dirt bike. Maybe you see a 2 horsepower gain on your YZ125 and that may not seem like much.
But, when you add 2 HP to a 30 HP bike, that’s almost a 7% improvement in power! I’m not saying that you’ll get that much just from a pipe on every bike, but you really have to look at the percentage of horsepower gain, rather than the HP number itself.
Not only that, but you have to look at the entire RPM range. If you’re looking for more low-end and midrange power, a specific pipe could give you 5-10% more torque over a 3000 RPM range.
Best exhaust for trail riding
Typically, you’ll want broader power with more low-end and midrange torque for off-road and trail riding. This makes it easier to ride because you can lug your 2 stroke at a lower RPM without needing to slip the clutch as much or stalling it as easily.
With more low-end torque, you can pop the front wheel up with less effort, which is really nice for getting over big logs and rocks on the trails.
Best 2 stroke pipe for trail riding:
- Stock - Good all around and no cost if you already have one!
- FMF Gnarly (Amazon) - Better low to midrange torque & durability
- Pro Circuit Platinum 2 (Amazon) - Better low to midrange torque & durability
- DEP Torque - Better low to midrange torque & durability
- Lexx Duraflow (Amazon) - less performance but cheaper
Best 2 stroke silencer for trail riding:
- FMF Turbinecore 2 (Amazon) - trail legal and less noise
- Pro Circuit Nature Friendly (MotoSport) - trail legal with no performance loss, but more noise
- Pro Circuit Type 296 (Amazon) - trail legal and less noise
Do you need to re-jet the carburetor after installing an aftermarket exhaust?
There are so many variables that it really depends on - but for the most part, yes, you will need to make a slight jetting adjustment to get the most performance and reliability if you change the exhaust on your 2 stroke dirt bike.
Not changing the jetting could make your dirt bike harder to start, have a poor throttle response, or even have less power. If you’re worried about making a jetting change to your 2 stroke in fear that you might mess something up, I’m here to tell you that it’s easier than you think.
You can get started tuning your carb jetting in just a few minutes using my FREE guide here.