Vertex Exhaust Gasket for Honda CRF250L, CRF300L and CRF450L/RL

The Vertex Exhaust Gasket (823075) is a high-grade OEM-replacement seal designed to restore an airtight, leak-free seal between the exhaust header pipe and the cylinder head exhaust port. Exhaust head pipe gaskets endure extreme heat cycles, engine vibration, and high exhaust gas pressures. Over time, original crush gaskets deform or degrade, leading to high-temperature gas leaks that cause lean air-fuel conditions, erratic idling, and excessive popping on deceleration.

Manufactured from high-density, heat-resistant composite materials with a crushable metal armor outer layer, this gasket compresses evenly upon installation to seal microscopic surface imperfections on both the exhaust port flange and header pipe. Precision-built to match exact OEM dimensions, it ensures a tight seal that maintains correct backpressure and exhaust scavenging performance.

Features:

• OEM Quality Sealing: Engineered to exact dimensional tolerances to provide a leak-free seal between the engine exhaust port and header pipe.

• Crush-Style Construction: Deforms under initial torque load to fill surface imperfections and pits on the cylinder head and exhaust pipe flange.

• Extreme Heat Resistance: Built with durable composite materials reinforced with steel/copper armor to withstand extreme exhaust gas temperatures without burning out.

• Prevents Decel Popping: Eliminates fresh air leaks at the header junction that cause lean conditions, popping on deceleration, and loss of low-end power.

• Direct Drop-In Replacement: Fits directly into the cylinder head exhaust socket with zero modification required.

What's in the Box:

• 1x Vertex Exhaust Gasket (Part #823075)

Fitment: 

• 2019–2020 – Honda CRF450L

• 2021–2026 – Honda CRF450RL

• 2021–2026 – Honda CRF300L & CRF300L Rally

• 2005–2026 – Honda CRF450X

• 2017–2020 – Honda CRF250L & CRF250L Rally

Fitment Notes:

• Single-Use Design: Exhaust head gaskets are designed to crush once during installation to form a seal. Always install a fresh gasket whenever the exhaust system or header pipe is removed for maintenance or engine service.

• Surface Cleaning: Thoroughly scrape out all remnants of the old gasket and clean carbon buildup from the exhaust port recess before inserting the new gasket.

• Why Gasket Reuse Fails: A common mistake during exhaust installs is reusing the old head pipe gasket. Because crush gaskets work by permanently deforming under the initial torque of the exhaust flange nuts, a used gasket has lost its elasticity and crush allowance. Reinstalling a used gasket almost guarantees an exhaust leak at the head, which draws oxygen into the exhaust stream and tricks the engine into popping heavily when rolling off the throttle.

• Torque Sequence Tip: When installing a new header pipe with the Vertex 823075 gasket, thread the exhaust flange nuts on hand-tight first to ensure the header pipe seats squarely into the gasket recess. Alternately torque the nuts in small increments up to the factory torque specification (typically 10–14 Nm / 88–123 in-lbs - Varify with service manual). Uneven tightening will cock the flange, crushing one side of the gasket flat while leaving an air gap on the opposite side.

Part Number: 823075