4" Heavy Duty Vinyl Bilge Blower Hose - 420-4

What This Blower Hose is Used For

Item 420-4 is used in compatible 4" marine ventilation systems to route intake and exhaust airflow through enclosed engine compartments.

Typical applications include:

• Bilge blower ducting
• Gasoline engine-compartment ventilation
• Powered exhaust ventilation systems
• Marine air-intake ducting
• Replacement of torn, crushed or deteriorated blower hose

Matching 4" Bilge Blower

4" Marine Bilge Blower - 5-3715

Matching 4" powered marine blower for compatible engine-compartment ventilation systems.

Pair the blower with 4" ducting when the boat's ventilation system is designed around a 4" hose diameter.

View 4" Bilge Blower

Matching 4" Hose Clamp

German-Style Hose Clamp - 4-17

Matching clamp for securing 4" blower hose to compatible blower outlets and marine ventilation fittings.

Proper clamping helps keep the hose connected despite engine vibration, boat movement and servicing inside the engine compartment.

View 4-17 Hose Clamp

3" and 4" Marine Blower System Guide

Need 3" Blower Hose Instead?

3" Heavy-Duty Vinyl Blower Hose - 420-3

Smaller 3" marine ventilation hose for systems designed around 3" blower ducting.

View 3" Blower Hose

3" Bilge Blower - 5-3710

Matching 3" marine blower for compatible ventilation systems using 3" ducting.

View 3" Bilge Blower

German-Style Hose Clamp - 4-13

Matching clamp for compatible 3" blower-hose installations.

View 4-13 Hose Clamp

Why Blower Hose Matters

The blower creates airflow, but the hose determines where that airflow is pulled from and where it is discharged.

If the ducting is torn, disconnected, crushed or badly kinked, the blower may continue running while the ventilation system is no longer moving air as intended.

For that reason, blower hose should be inspected whenever the blower, engine compartment or surrounding ventilation system is serviced.

Blower Hose Installation Tips

• Match hose diameter to the blower and ventilation fittings.
• Use the correct clamp at blower and vent connections.
• Keep ducting as short and direct as practical.
• Avoid severe bends that restrict airflow.
• Do not crush the flexible hose behind batteries or stored gear.
• Support long sections so they do not sag into bilge water.
• Keep hose openings clear of debris.
• Inspect the hose for tears and disconnected sections.
• Verify airflow after replacing any part of the ventilation system.

When Should 4" Blower Hose Be Replaced?

Replace marine ventilation hose when it no longer provides an open, securely connected path for airflow.

Common signs include:

• Torn or punctured hose
• Collapsed ducting
• Severe kinks
• Cracking or deterioration
• Loose blower or vent connections
• Hose damaged by engine-compartment heat
• Hose crushed by batteries, storage or other equipment

Marine Wiring Supplies

If blower hose replacement is part of a larger ventilation-system repair, inspect the blower wiring and connections at the same time.

Blue Butt Connectors - BBC - 25 Pack

Electrical butt connectors for compatible bilge blower and marine wiring repairs.

View Blue Butt Connectors

1/4" Red Heat Shrink - 14R

Red heat-shrink tubing for protecting compatible electrical connections and identifying positive wiring.

View Red Heat Shrink

1/4" Black Heat Shrink - 14B

Black heat-shrink tubing for protecting compatible marine electrical connections.

View Black Heat Shrink

Key Features and Benefits

• 4" diameter marine ventilation hose
• Heavy-duty vinyl construction
• For compatible bilge blower and engine-compartment ventilation systems
• Matching 4" bilge blower available
• Matching German-style 4-17 clamp available
• Complete 3" blower system also available
• Flexible construction for routing through marine engine compartments
• Marine wiring supplies available for complete blower-system service

FAQ

What size is item 420-4?
Item 420-4 is 4" heavy-duty vinyl marine blower hose.

What blower goes with this hose?
Pro Marine stocks the 5-3715 4" Bilge Blower for compatible 4" ventilation systems.

Which clamp should I use?
Use the German-Style 4-17 Hose Clamp .

Can I use 3" hose on a 4" blower?
Do not reduce the system simply because smaller hose is available. Match the ducting to the blower and the boat's original ventilation design.

Why is blower hose important?
Blower hose directs the airflow created by the ventilation blower. Torn, crushed or disconnected hose can reduce the effectiveness of the system.

Should the hose have sharp bends?
Avoid sharp bends and kinks whenever possible because they can restrict airflow through the ventilation system.

Do you carry a 3" blower system?
Yes. Pro Marine stocks the 3" bilge blower, 3" blower hose and 4-13 clamp.

Do you carry blower wiring supplies?
Yes. Pro Marine stocks blue butt connectors, red heat shrink and black heat shrink.

Searchable Terms

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