Attwood Marine Tsunami Bilge Mk2 Bilge Pump Service Kit, For S500 & S800, 3/4 in and 1 in Outlets

Overview

The Attwood Marine AK5505-7 is a service kit for S500 and S800 bilge pumps, with outlet sizes in 3/4" (19 mm) and 1" (25 mm), and compatibility with Tsunami Bilge Mk2 setups. It covers the discharge-side service parts that commonly need replacement, including a 90-degree outlet, a straight outlet, a washer, and a non-return/check valve.

This kit makes sense when an existing pump is still in place and the job is focused on refreshing the outlet hardware rather than replacing the whole pump. On boats where bilge access is tight, having both a straight outlet and a 90-degree outlet in the same kit helps when the hose run needs to stay direct or turn immediately to clear nearby structure or equipment.

Key features

• Fits Attwood S500 and S800 bilge pump service applications and is compatible with Tsunami Bilge Mk2
• Includes both straight and 90-degree outlet fittings for different hose routing layouts
• Covers 3/4" (19 mm) and 1" (25 mm) outlet sizing used on these pump installations
• Adds a replacement washer and non-return/check valve for outlet-side service work
• Useful when the goal is to keep an existing pump installation in service without sourcing each outlet part separately

Compatibility and fit

This service kit is for the S500 and S800 pump size range, not the larger S1200 size. Before ordering, check the pump model on the housing and confirm whether the discharge hose on the boat is 3/4" or 1".

It is a good match for owners maintaining an existing bilge pump installation on a runabout, center console, fishing boat, or small cruiser where the pump is still sound but the outlet pieces or check valve need attention.

Installation and setup

Match the outlet style to the way the hose leaves the pump. The 90-degree outlet is useful when the discharge hose needs to turn right away above the pump, while the straight outlet suits runs with a more direct path.

When servicing the pump, inspect the sealing surfaces and the discharge hose at the same time. In a bilge compartment, it is much easier to replace worn outlet-side parts while everything is already apart than to reopen the area later for a small leak or a sticking check valve.

What's included

• 90-degree outlet
• Straight outlet
• Washer
• Non-return/check valve

Shipping
We ship worldwide from the United States. Rates are calculated at checkout based on destination and package weight. Some items include free shipping, which will show automatically. Not every product is eligible for international shipping; checkout will confirm eligibility. We do not ship to PO Boxes except through USPS, and not all packages qualify.

Processing and dispatch
Most orders are verified, packed, and handed to the carrier within 1 to 2 business days. Some products may need extra handling time or ship directly from the manufacturer. For certain international orders, inventory transfers between warehouses may add time. If any delay is expected, we will let you know the dispatch date.

Delivery and tracking
Deliveries are handled by trusted carriers such as USPS, UPS, FedEx, and DHL. Estimated arrival times appear at checkout and depend on your location and the service you choose. These are estimates and can be affected by customs or carrier disruptions. A shipping confirmation with a tracking link is emailed when your order ships, and tracking may take up to 24 hours to update. You can also view tracking in your account.

Duties, taxes, and support
International customers are responsible for any customs duties, taxes, and fees charged by the destination country. If these charges are refused and a shipment returns to us, the carrier’s return cost and any re-entry customs fees will be deducted from the refund. If your order is late or you need help, contact cs@qualityboatparts.com and we will assist you.

Quality Boat Parts is a reseller. Many items include a manufacturer’s warranty, and all warranty service is handled directly by the manufacturer. We do not manage or administer warranty claims on behalf of customers.

Warranty terms, coverage, and duration are set by each manufacturer. Issues involving defects, repairs, or replacements must be addressed with the manufacturer’s support team. When available, the warranty period is listed on the product page. If it is not shown, contact us or the manufacturer for details before purchasing.

To start a claim, the customer must contact the manufacturer and follow their process. Keep your proof of purchase and original packaging, and register the product if the manufacturer requires it, as these are often needed for warranty service.

We are happy to help you find the right contact or documentation, but we cannot decide outcomes or intervene in claim resolutions. For guidance, email cs@qualityboatparts.com.