420950840 Water Pump Housing Gasket for Sea-Doo Fish 21-300 1630 2026

Water Pump Housing Gasket for Sea-Doo Fish 21-300 1630

This water pump housing gasket for Sea-Doo seals the pump housing to the engine block on the Fish 21-300 1630, keeping coolant where it belongs; it cross-references OEM 420950840.

Overview

This water pump housing gasket for Sea-Doo is a direct-fit sealing component for the Fish 21-300 1630 platform. It seals the joint between the water pump housing and the engine, preventing coolant leaks, maintaining proper flow, and protecting the cooling system from pressure loss. It is aimed at owners and mechanics performing routine pump service or a full rebuild on a 2026 model.

Built For Performance

• Precision-cut to match the pump housing mating surface
• Seals coolant passages under operating temperature and pressure
• Resists swelling, cracking, and coolant breakdown over time
• Cross-references OEM part number 420950840
• Thin profile maintains correct housing-to-block clearance
• Installs with standard pump service tools

Fits These Machines

• for Sea-Doo Fish 21-300 1630, 2026

On-The-Job Use

• Water pump housing resealing during routine service
• Cooling system repair after a leak is traced to the housing joint
• Full pump rebuild on a 2026 Fish 21-300 1630
• Preventative replacement during engine-out service work

Specs At A Glance

Good To Know

Q: Does this gasket come as a single unit or in a set? A: It is supplied as one water pump housing gasket sized for the Fish 21-300 1630. Confirm whether your service procedure calls for additional seals or O-rings before ordering.

Q: Can this gasket be reused if the housing is removed again? A: Gaskets of this type are not intended for reuse once compressed. Fit a fresh gasket any time the pump housing is separated to keep the coolant seal reliable.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.