Mercruiser Engine

What is Type A1 Marine Fuel Hose?

Type A1 marine fuel hose is designed for fuel-feed applications requiring a marine hose with enhanced fire-resistant performance.

Type A1 hose is commonly used in permanent marine fuel systems and installations where the fuel line passes through enclosed or below-deck areas.

When selecting fuel hose, both the inside diameter and the required hose classification should be verified for the installation.

Why Use 1/2" Fuel Hose?

A 1/2" fuel line provides greater internal flow area than the more common 1/4", 5/16" and 3/8" marine fuel hoses.

It may be used in applications where the engine or fuel-system design requires a larger fuel supply line to support higher fuel-flow demand.

Always follow the engine or boat manufacturer's required hose diameter rather than increasing or decreasing hose size without verifying the fuel-system requirements.

Matching Fuel Hose Clamp

German-Style Hose Clamp - 4-4

Recommended hose clamp for the MPI 360-12 1/2" Type A1 marine fuel hose.

German-style hose clamps provide a secure connection for larger marine fuel-hose applications.

View German-Style Hose Clamp

Fuel Line Tools and Clamp Assortment

Oetiker Standard Jaw Pincer Tool

Useful installation tool for Oetiker ear clamps used throughout many marine fuel-line systems.

While this 1/2" hose uses the German-style clamp shown above, the pincer tool is useful when servicing other fuel-hose sizes that use Oetiker ear clamps.

View Oetiker Pincer Tool

Oetiker Clamp Pack with Tool

Complete assortment of common Oetiker clamp sizes with the installation tool included.

A convenient option for marine shops and technicians servicing different fuel-hose sizes throughout a boat or engine.

View Oetiker Clamp Pack

What This Fuel Hose is Used For

MPI 360-12 is used when building, repairing or replacing a marine fuel supply line requiring 1/2" Type A1 hose.

Typical applications involve larger marine fuel systems where increased fuel-flow capacity is required and the installation calls for Type A1 hose.

Typical 1/2" Fuel-Line Setup

Depending on the boat and engine, a 1/2" marine fuel-line installation may include:

• MPI 360-12 1/2" Type A1 marine fuel hose
• German-style 4-4 hose clamps
• Fuel tank pickup or shutoff valve
• Fuel/water separator or filter assembly
• Engine fuel-system connection
• Application-specific fittings and adapters

Primer Bulb vs. Larger Fuel Systems

Smaller outboard fuel systems commonly use 1/4", 5/16" or 3/8" hose with an inline primer bulb.

A 1/2" fuel supply line generally indicates a higher-flow fuel system, and a hand primer bulb is not normally part of that configuration.

The engine manufacturer's fuel-system requirements should always take priority when determining hose size, fittings, filters and priming components.

Fuel Hose Size Comparison

Key Features & Benefits

• 1/2" inside diameter
• MPI Products marine fuel hose
• Type A1 marine fuel-hose classification
• Designed for fuel-feed applications requiring Type A1 hose
• Suitable for higher-flow marine fuel systems
• Common choice for enclosed or below-deck fuel-line routing when 1/2" hose is required
• Matching German-style 4-4 hose clamp available
• Primer bulb normally not used with 1/2" fuel-line systems
• Fuel-system installation tools and clamp assortment available

Need Help Choosing the Right Marine Fuel Hose?

Fuel-line diameter, Type A or Type B classification, fuel-system flow requirements, fittings, filters and clamp selection all need to match the boat and engine installation.

Visit the Pro Marine Fuel Line Technical Center

FAQ

What size is MPI 360-12?
This fuel hose has a 1/2" inside diameter.

What type of fuel hose is 360-12?
It is Type A1 marine fuel hose.

What is Type A1 fuel hose used for?
Type A1 is used for marine fuel-feed applications requiring the additional fire-resistant performance associated with Type A hose.

Can this hose be used below deck?
Type A1 hose is commonly used in enclosed and below-deck fuel-system installations when the fuel system calls for this hose size and classification.

Which clamp fits this 1/2" hose?
Use the German-Style 4-4 Hose Clamp .

Does this hose use an Oetiker ear clamp?
The recommended clamp for this hose is the German-style 4-4 hose clamp.

Does 1/2" fuel hose use a primer bulb?
A primer bulb is not normally used in a fuel system requiring 1/2" hose. Larger lines are typically used in higher-flow fuel systems with a different priming and fuel-delivery arrangement.

Should I use 1/2" hose just to increase fuel flow?
Use the hose diameter specified for the engine and fuel system. Increasing hose size without verifying the complete system is not a substitute for following the manufacturer's fuel-system requirements.

Do you sell fuel-line clamp tools?
Yes. Pro Marine stocks the Oetiker Standard Jaw Pincer Tool for fuel-line applications using Oetiker ear clamps.

Do you sell a complete clamp assortment?
Yes. The Oetiker Clamp Pack with Tool includes commonly used clamp sizes and an installation tool.

Searchable Part Numbers & Terms

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