Introduction to Dual Outlet Quad Exhaust Systems

Upgrading your ATV with a dual outlet quad exhaust system is one of the most effective modifications you can make for both performance and aesthetics. Unlike a single exhaust, a dual outlet setup improves exhaust gas flow, reducing back pressure and allowing the engine to breathe more freely. This typically results in a noticeable increase in horsepower and torque, especially in the mid-to-high RPM range. The aggressive, symmetrical look of quad outlets also gives your machine a more purposeful stance, whether you are riding trails, dunes, or tackling mud bogs.

However, a successful installation requires more than just bolting on new parts. You must understand your ATV’s specific mounting geometry, ensure proper sealing to avoid exhaust leaks, and often make complementary adjustments to the fuel system or ECU. This article covers every detail of the installation process, from selecting the right kit to final tuning, so you can maximize the benefits of your new exhaust system.

Tools and Materials You Will Need

Before beginning the job, gather all necessary equipment. Having everything at hand prevents frustrating interruptions and ensures you can work efficiently.

Essential Hand Tools

  • Socket set – Metric and SAE sockets (typically 8mm, 10mm, 12mm, 14mm) with ratchets and extensions for reaching tight bolts.
  • Combination wrenches – Open-end and box-end wrenches in the same sizes for stubborn fasteners.
  • Screwdrivers – Flathead and Phillips for clamps, brackets, or heat shield fasteners.
  • Torque wrench – Critical for tightening bolts to manufacturer specifications and preventing warping of flanges.
  • Wire brush or drill with wire wheel – For cleaning rust and debris from mounting surfaces.

Consumables and Safety Gear

  • Penetrating oil (e.g., PB Blaster or WD-40) – Loosens corroded bolts and reduces the risk of snapping them.
  • Anti-seize compound – Applied to bolt threads before installation to prevent galling and future seizure.
  • Exhaust gasket set – Replace all gaskets (manifold to header, mid-pipe connections, muffler joints) with high-quality graphite or copper ones.
  • New exhaust system kit – Ensure it is specifically designed for your ATV make, model, and year. Dual outlet quad kits often include Y-pipes, mufflers, hangers, and hardware.
  • Protective gloves – Mechanic’s gloves resist cuts and heat.
  • Safety glasses – Shield eyes from debris and dripping fluids.
  • Jack or ATV lift – Optional but highly recommended for safe, comfortable access underneath the vehicle.

Optional but Helpful Items

  • Exhaust hanger removal tool – If your ATV uses rubber isolators, this tool simplifies removal.
  • Dremel or cut-off wheel – For cutting stubborn bolts or modifying brackets.
  • Shop vacuum – To clean out loose debris from the exhaust port area before installing the new system.

Preparation: Setting Up for Success

Safe Work Environment

Park your ATV on a level, well-ventilated surface. If you are working indoors, open the garage door and run a fan to move exhaust fumes away. Engage the parking brake and chock the wheels to prevent accidental movement. Allow the engine and exhaust components to cool completely – exhaust pipes can remain hot enough to cause burns for over an hour after riding.

ATV Positioning and Access

If you have a lift or a sturdy set of ramps, raise the ATV enough to slide under it comfortably. Never work under a machine supported only by a scissor jack; use axle stands or a dedicated ATV lift. Remove any skid plates, splash guards, or heat shields that obstruct access to the exhaust mounting points. Take photos of the existing routing before disassembly – these are invaluable when reconnecting hangers and brackets.

Removing the Old Exhaust System

Initial Disassembly

Start by spraying penetrating oil on all exhaust bolts, especially those at the cylinder head manifold and the hanger connections. Allow the oil to soak for 10–15 minutes. Using your socket set, loosen the bolts that secure the muffler to its bracket and the header pipe flanges. Work from the rear of the system forward: detach the muffler from the mid-pipe, then unbolt the header from the engine. If your ATV has an oxygen sensor in the exhaust stream, carefully disconnect its wiring harness and remove the sensor using a special O2 sensor socket or a box-end wrench.

Dealing with Rust and Stubborn Bolts

If any bolt resists, apply more penetrating oil and use a breaker bar or impact driver with controlled bursts. Heating the area around a seized bolt with a propane torch can expand the metal and break the bond, but be cautious near fuel lines or plastic components. As a last resort, use a bolt extractor set or carefully drill out the bolt and re-tap the threads. Replacing damaged hardware is far better than risking a broken bolt inside the cylinder head.

Cleaning Mounting Surfaces

Once the old exhaust is completely removed, inspect the exhaust port on the cylinder head and all mounting flanges. Use a wire brush or a drill-mounted wire wheel to remove carbon deposits, rust, and old gasket material. Any residue left behind will compromise the seal of your new system and can cause exhaust leaks. After cleaning, wipe the surfaces with a rag dipped in brake cleaner to remove oils and fine particles.

Installing the New Dual Outlet Quad Exhaust

Dry Fit and Alignment

Before applying any sealants or anti-seize, loosely assemble the entire new exhaust system outside the vehicle. This dry fit lets you verify that all pipes, Y-connectors, and mufflers align correctly without interference from the frame, suspension, or swingarm. Many quad exhaust kits include rubber hangers or metal straps – check that the muffler outlets are symmetrically positioned and that the tips clear the rear bumper or grab bar. Make any necessary adjustments by rotating slip joints or bending hanger tabs slightly with pliers.

Installing the Header and Mid-Pipe

Begin with the header pipe. Place a new gasket (usually a crush ring or a metal-encased graphite gasket) into the exhaust port on the cylinder head. Slide the header flange over the pipe and insert the header into the port. Hand-tighten the flange nuts or bolts before moving on. Connect the mid-pipe or Y-section to the header using the provided clamp or spring clips. Do not fully tighten anything yet.

Mounting the Mufflers and Quad Outlets

Hang each muffler on its designated bracket, inserting rubber isolators or metal sleeves as required. The dual outlets should point rearward and have equal clearance from the tires and bodywork. If your kit uses a single muffler body with dual tips, position the muffler first, then attach the outlet pipes. Once all components are loosely connected, step back and inspect the overall alignment. Rotate the muffler cans so the logos or designed orientation is correct.

Torquing and Sealing

When you are satisfied with the fit, apply a small amount of anti-seize compound to the threads of all bolts that contact aluminum or steel parts. For the header nuts, use a torque wrench to tighten them to the factory specification – typically between 15 and 25 ft-lbs depending on your ATV model. Over-tightening can distort the flange or strip the threads. Tighten the muffler hanger bolts and mid-pipe clamps firmly but avoid bending the brackets. Some systems incorporate springs that hold slip joints together; ensure the springs are evenly tensioned.

Reinstalling Sensors and Heat Shields

If your ATV has an oxygen sensor, reinsert it using a new anti-seize compound on the threads (do not use standard anti-seize – use sensor-safe copper-based compound). Torque the sensor to the manufacturer’s specification. Reattach any heat shields you removed, ensuring they do not contact the exhaust directly, which could cause rattling or heat transfer issues.

Performance Tuning and Fuel System Adjustments

Why Jetting or Tuning May Be Needed

A dual outlet quad exhaust system increases exhaust flow, which leans out the air-fuel mixture. On carbureted ATVs, you may need to rejet the carburetor to a larger main jet and possibly adjust the pilot jet or needle position. On fuel-injected models, a piggyback tuner or ECU flash can correct the air-fuel ratio and prevent the engine from running too lean, which can cause overheating or detonation.

Steps for Carbureted ATVs

  • Remove the carburetor and note the current jet sizes.
  • Install a main jet that is 2–4 sizes larger than stock (consult your exhaust kit’s recommendations).
  • Adjust the idle mixture screw for optimal throttle response.
  • Test ride and check spark plug color – a tan or light brown center electrode indicates a correct mixture; white or gray signals a lean condition.

Steps for Fuel-Injected ATVs

  • Use a handheld tuner (such as Dynojet Power Commander or EJK) to map fuel adjustments at various throttle positions.
  • Or have the ECU reflashed by a professional tuner who has experience with your specific ATV model.
  • Monitor intake air temperature and engine temperature during initial runs to ensure safe operation.

Failure to tune the engine after an exhaust upgrade can result in reduced performance, poor throttle response, and even engine damage over time. Always prioritize proper tuning alongside the installation.

Final Checks and Testing

Visual Inspection and Leak Testing

Lower the ATV back to the ground. With the engine off, check that all bolts, clamps, and springs are tight. Start the engine and let it idle. Place your hand near each joint (without touching hot metal) to feel for escaping air. You can also spray a soapy water solution on the connections; bubbles will indicate a leak. Tighten or reseal any leaking joints immediately.

Noise and Vibration Assessment

Listen for unusual rattling, tinny vibrations, or excessive drone. Many quad exhausts are louder than stock – that is expected – but mechanical rattles suggest a loose hanger or a pipe contacting the frame. Let the engine warm up fully and then rev it through the RPM range (under no-load conditions in neutral) to confirm nothing touches the frame, plastics, or brake lines.

Test Ride

Take a short, careful ride in a safe area. Accelerate gradually, then full throttle, and decelerate to listen for changes in sound. Pay attention to any new engine hesitation or surging, which may indicate a tuning issue. Stop after 5–10 minutes and re-torque the header nuts while they are warm – slight thermal expansion can loosen initial torque. Also, inspect the exhaust hangers for signs of stress or deformation.

Maintenance Tips for Longevity

  • Rust prevention – After washing your ATV, dry the exhaust pipes thoroughly. Apply a high-temperature rust inhibitor or ceramic coating to exposed metal surfaces to resist corrosion.
  • Regular bolt checks – Every 100 miles or after particularly rough rides, inspect all exhaust fasteners. Vibration can loosen them over time.
  • Clean the tips – Carbon buildup on the quad outlets can be removed with a soft brush and degreaser. Avoid abrasive polishes that may damage chrome or painted finishes.
  • Re-torque after initial heat cycles – After the first three to four rides (allowing the system to fully cool between rides), re-check torque on the header nuts and muffler brackets.
  • Gasket inspection – Replace gaskets whenever you remove the exhaust system for other repairs. A leaking gasket wastes performance and can create dangerous carbon monoxide exposure.

Troubleshooting Common Installation Issues

Exhaust Leaks at the Header

If you hear a ticking sound during idle that disappears as the engine warms up, the header gasket may not be fully seated. Remove the header, inspect the gasket for damage, and reinstall with fresh anti-seize on the studs. Ensure the flange is not bent.

Muffler Hanger Breakage

High-performance exhaust systems are heavier than stock ones. If your ATV’s rubber hangers tear or metal brackets crack, consider upgrading to aftermarket heavy-duty hangers or reinforcing the mounting points with additional brackets.

Unwanted Drone or Resonance

Some quad exhausts produce a low-frequency drone at cruising RPM. Wrapping the mid-pipe with exhaust heat wrap can dampen resonance, but verify that the wrap does not contact wiring or plastic. Alternatively, adding a small resonator tip may change the sound profile.

Check Engine Light Illuminates

On fuel-injected ATVs, removing the oxygen sensor or changing the exhaust flow can trigger a code. Use a diagnostic tool to read the code – often it is related to a downstream O2 sensor that monitors catalyst efficiency. If your ATV has a catalytic converter and you removed it, you may need a tune to disable the related error codes.

Additional Resources

For more detailed torque specifications and model-specific installation tips, refer to your ATV’s service manual. Online communities such as ATV Rider forums and YouTube tutorials for your exact model can provide visual guidance. Quality exhaust kits from brands like HMF Engineering or Yoshimura include detailed instructions and support. For carburetor tuning, consult the Jets R Us jetting guide or Dynojet’s fuel mapping database.

Installing a dual outlet quad exhaust system on your ATV is a rewarding project that transforms both sound and performance. With careful preparation, correct tools, and attention to alignment and tuning, your upgraded exhaust will provide reliable, exciting power for many seasons of riding.