Seaworks Boat Engine Winterizer Kit with Gravity-Flow Flusher for Inboard & Outboard Engines

Seaworks Boat Winterizer is a gravity-flow engine flushing and winter-preparation kit for inboard and outboard boat engines, with an included flusher and an antifreeze tank with an on/off valve.

• Gravity-flow system for winter preparation — flushes and prepares the engine for winter storage.
• For inboard and outboard engines — supports use with either engine type, subject to the front-pump limitation below.
• Tank, valves, T-connector, braided hose with fittings, and flusher included — key kit components are supplied together.
• Requires 5 gallons of compatible antifreeze with burst protection of at least -50°F (-45.6°C) — antifreeze is not included.
• Front engine-mounted raw water pumps need a separate front engine pump adapter for a suction-side connection — the adapter is not included.

Preparing a marine engine for winter storage involves flushing it and using antifreeze to help protect the engine. The Seaworks kit brings the flow components and flusher together in a gravity-operated setup for DIY winter preparation. It is intended for regular use to help clean impurities from the engine; its fittings are designed to maintain antifreeze flow through the system.

What does the Seaworks Boat Winterizer do?

The kit flushes and prepares a boat engine for winter storage, while its fittings are designed to provide uninterrupted antifreeze flow. Regular use is intended to clean impurities and support engine performance and life expectancy. The system uses gravity flow rather than a powered pump, and the flusher is part of the kit.

• Made for marine engine winter preparation.
• Designed for flushing with compatible antifreeze.
• Use at regular intervals to clean impurities.

What comes with the Seaworks Boat Winterizer kit?

The kit includes an antifreeze tank with an on/off valve, a T-connector, a shutoff valve, a braided hose with fittings, and a flusher. These components form the flow system used to connect and direct antifreeze through the engine setup. Antifreeze itself must be supplied separately, and the required amount for boat winterization is 5 gallons.

• Tank with on/off valve for controlling flow from the tank.
• T-connector, shutoff valve, and braided hose with fittings.
• Flusher included; antifreeze not included.

Will it connect to a front engine-mounted raw water pump?

For a front engine-mounted raw water pump, including most Volvo and inboard setups, a separate Front Engine Pump adapter is needed to connect directly to the suction side. Do not connect the kit directly to that suction side without the adapter, and do not use this method to winterize a front engine-mounted raw water pump system. This connection requirement is important when checking whether the kit suits your engine layout.

• Front Engine Pump adapter is not included.
• Do not attempt a direct suction-side connection without the adapter.
• Do not use this method for a front engine-mounted raw water pump system.

The Seaworks Boat Winterizer is suited to boat owners preparing compatible inboard or outboard engines for winter storage with a gravity-flow flushing kit. Choose antifreeze that meets the stated burst-protection threshold, and account for the separate adapter requirement if your setup has a front engine-mounted raw water pump. Its included flusher and flow components make it a winter-preparation kit for engines rather than a standalone antifreeze product.