Indmar Marine Exhaust Elbow – Catalyst Extended Port | Part #585017

Keep your exhaust system flowing freely and your engine running clean with this genuine Indmar catalyst exhaust elbow, extended port design. A critical component in your Indmar marine exhaust system — the exhaust elbow directs hot exhaust gases away from the engine while the integrated catalyst helps reduce harmful emissions, keeping your boat compliant with Australian marine environmental standards.

What does the exhaust elbow do?
The exhaust elbow connects your engine's exhaust manifold to the exhaust system and directs gases overboard. The extended port design provides:

• Improved exhaust flow and scavenging for better engine performance
• Increased clearance in tight engine bay configurations
• Reduced back pressure for improved fuel efficiency
• Better heat management away from sensitive engine components

What is a catalyst exhaust elbow?
Unlike a standard exhaust elbow, the catalyst version incorporates an emissions reduction element that helps break down harmful exhaust gases before they exit the boat. This is increasingly important on Australian inland waterways, lakes, and reservoirs where environmental regulations around vessel emissions are tightening. Running a catalyst exhaust system keeps you compliant and protects the waterways you love.

When should you replace it?
Exhaust elbows are one of the most commonly neglected service items on marine engines — yet one of the most important. Replace your exhaust elbow if you notice:

• Visible cracks, pitting, or corrosion on the elbow body
• Exhaust gases or water leaking at the manifold connection
• Overheating issues — a restricted elbow reduces cooling water flow
• Carbon build-up causing restricted exhaust flow
• Unusual exhaust smell or smoke colour changes
• Any physical damage from impact or overtightening

How often should you inspect it?
Inspect your exhaust elbow every season. Carbon build-up and corrosion can develop quickly in marine exhaust systems — particularly in boats that see heavy use or operate in salt-influenced environments. Early replacement is far cheaper than the engine damage a failed elbow can cause.

Pro tip: When replacing your exhaust elbow always replace the gasket at the same time — 765006 Exhaust Elbow Catalyst Gasket 5.7L. Reusing old gaskets on a new elbow is a false economy — a leaking exhaust gasket can allow water back into the engine, causing catastrophic and expensive hydro-lock damage. Always buy them together.

Compatible with: Indmar 5.7L marine engines fitted to Malibu, Moomba, Supra, and Tige boats. Contact us to verify fitment for your specific model year before ordering.

Pairs perfectly with:

• 765006 – Exhaust Elbow Catalyst Gasket 5.7L
• 735020  -  V-Band Clamp  Cat Exhaust

Features:

• Genuine Indmar OEM part
• Extended port design for improved exhaust flow
• Integrated catalyst for emissions reduction
• Engineered for Indmar 5.7L marine exhaust systems
• Corrosion resistant construction for marine environments
• Direct replacement — no modifications needed

Part Number: 585017
In stock and shipped fast from Australia 🇦🇺