The most widely used dirt bike in professional racing is the 4-stroke. It's the engine that propelled Ricky Carmichael to GOAT status, is helping Ryan Villopoto create his own dynasty and helping develop and usher in a slew of amateur talent to the pro ranks.

The 4-stroke bike is the fastest on the market and unlike its 2-stroke counterpart the need to mix fuel and oil together is eliminated. The competition between the 4-stroke folks and the 2-stroke folks is strong and each side offers reasonable arguments as to which bike is better. We're not here to take sides! Different strokes for different folks as they say.

If you're looking to upgrade or replace the exhaust system on your 4-stroke you've come to the right place. As you'll see the number of available 4-stroke exhaust system is vast when compared to 2-stroke systems. The difference is the focus on increasing power or performance is less a variable than weight management and cost.

It's pretty easy to identify a 4-stroke exhaust design from a 2-stroke exhaust design. The 2-stroke exhaust system uses an expansion chamber - the prominent bulge in the exhaust pipe - to increase the engine's horsepower. You'll notice the 4 stroke exhausts do not have this as they rely on the exhaust valves opening and closing to control the exhaust pulses as they enter the exhaust system.

Four-stroke cycle used in gasoline/petrol engines. 1 - Intake, 2 - Compression, 3 - Power, 4 - Exhaust. Source: Wikipedia

If you're new to riding or looking to replace or upgrade existing 4-stroke exhaust pipes then this guide is your first stop. Here is how to pick the best 4-stroke exhaust system for your bike.

Complete 4-Stroke Exhaust Pipes

If you are set on boosting power and performance the best way to accomplish this with a 4-stroke engine is a complete overhaul of your exhaust system from the cylinder head through the muffler. Much of the performance gain is attributable to the potential significant loss of weight of your bike, depending on the material used to construct the exhaust system. The common components used to construct 4-stroke exhaust systems include:

  • Aluminum muffler with stainless steel header and mid pipe
  • Titanium muffler with titanium header and mid pipe
  • Carbon fiber can with titanium header and mid pipe

Motocross/Supercross Full Exhaust Systems

Exhaust systems for the track tend to be lighter giving racers more edge in a sport where every ounce counts. The lighter materials like carbon fiber add expense and stand-up to the grueling and intense hard track riding. However, they can dent and damage easier compared to heavier weight materials.

Budget-Friendly

Mid-Range

Top of the Line

Two Brothers M-7

Pro Circuit T-4 GP Complete Exhaust

Yoshimura RS-4

Price: $494.98 - $503.98

Price: $697.99 - $725.99

Price: $695.77 - $945.00

Features:

  • Deep throaty sound
  • Aluminum construction
  • Fully serviceable if damaged

Features:

  • Lightweight 6061 T-6 aluminum sleeve
  • Removable U.S.F.S.-approved spark arrestor
  • RC-4 Resonance Chamber to reduce noise
  • Billet aluminum mounting bracket

Features:

  • Titanium/Carbon Fiber
  • Extremely light
  • Duplex chamber
  • Carbon cone and cap
 

Off-Road Full Exhaust Systems

Off-road exhaust systems bring durability to weather rocks, logs and whatever the trails can throw at your bike. Stainless steel and aluminum compose most construction materials entwined with lighter materials like titanium.

Budget-Friendly

Mid-Range

Top of the Line

FMF Powercore 4 Slip on with FMF Powerbomb Header

Dr.D Complete Stainless Steel

FMF Factory 4.1 with Powerbomb Header

Price: $173.77 - $296.99 and $157.99 - $269.99

Price: $215.99 - $521.99

Price: $539.98 - $764.98

Features:

  • Stainless Steel
  • Quiet Sound
  • Maximized Power

Features:

  • Aluminum muffler with magnesium end cap
  • Stainless Steel head and mid pipe for durability
  • Simple repacking

Features:

  • Massive Power gains throughout the RPM range
  • More power
  • Slip-on constructed with aerospace material
  • Quieter than stock
 

Motocross/Supercross Slip-ons

Budget-Friendly

Mid-Range

Top of the Line

FMF Powercore 4 Slip-On

Yoshimura RS-4 Comp Series

FMF Factory 4.1 Slip-On - Natural Titanium

Price: $173.77 - $296.99

Price: $355.50 - $382.50

Price: $359.99 - $449.99

Features:

  • Durable
  • Advanced packing material
  • Stainless steel and aluminum construction

Features:

  • Aluminum sleeve
  • Stainless steel tail pip
  • Carbon fiber end cap
  • Weight reduction

Features:

  • Boosts low-end torque
  • Big weight reduction
  • Available with titanium or stainless steel mid pipe
 

Off-Road Slip-Ons

Off-road slip-ons are constructed with stronger materials like off-road exhaust systems in order to increase durability and longevity on the trails.

Budget-Friendly

Mid-Range

Top of the Line

Big Gun Eco System

Bill's Pipes SA-4 Series Slip-On Exhaust

FMF Factory 4.1 Titanium RCT - Carbon Fiber

Price: $243.95

Price: $190.77 - $339.99

Price: $629.99 - $809.99

Features:

  • Stainless steel pipe
  • Brushed aluminum housing
  • Power increase

Features:

  • Lightweight brushed aluminum muffler
  • TIG welded reinforced muffler bracket
  • Increased horsepower and torque gains
  • Removable screen-type spark arrestor included

Features:

  • Big weight savings
  • Power increase
  • Proprietary packing blend
  • Use with FMF Header or stock

4-Stroke Spark Arrestors

Most aftermarket 4-stroke slip-ons already contain spark arrestors or are customizable to run with a spark arrestor. If you are happy with your stock muffler or upgrading is not an option and you require a spark arrestor then we'd suggest the following spark arrestors:

Spark Arrestors

Pro Moto Billet Spark Arrestor

Price: $99.99 - $259.95

Features:

  • Prevents replacing existing system
  • Anodized to match factory color
  • Designed to fit stock pipes
 

For those who prefer an ultra-quiet spark arrestor:

Ultra-quiet Spark Arrestor

FMF Q4 Spark Arrestor

Price: $198.77 - $341.99

Features:

  • Ultra quiet (max. 96 dB)
  • Maintenance free arrestor
  • Aircraft-grade aluminum and high-strength stainless steel
 

Written By: AndrewT