CARBBIA Marine Thermostat Kit 160°F for Mercruiser GM V6/V8 (1987+), with Plastic Sleeve and Gaskets

CARBBIA 807252Q5 is a complete 160° thermostat kit with a protective plastic sleeve and multiple gaskets designed to replace factory units on 1987‑up Mercruiser GM V6 and V8 marine engines.

This kit gathers the parts you need for a reliable thermostat replacement: a 160°F thermostat matched to common Mercruiser part numbers, a plastic sleeve for correct seating, and the required cover and housing gaskets. It fits GM‑based marine engines (4.3L, 5.0L, 5.7L, 7.4L, 8.2L) from 1987 and later, and is compatible with several OEM part listings such as Merc 807252Q5 and GLM 13101. The kit is intended for standard cooling systems and provides a cost‑effective way to restore thermostat function and sealing without sourcing multiple components separately.

Which engines and model years will this CARBBIA thermostat kit fit?

This kit is engineered for GM‑based Mercruiser marine engines built 1987 and later. It covers both small‑block V6 and V8 displacements commonly found in recreational boats, ensuring interchangeability with many factory parts.

• Compatible with Mercruiser V6 & V8: 4.3L, 5.0L, 5.7L, 7.4L, 8.2L (1987‑up).
• Matches Merc OEM references including 807252Q5 and related numbers.
• Also cross‑referenced to GLM part 13101 and Sierra 18‑3647 (note: Sierra version lacks plastic sleeve).

What parts are included in the package and why each matters?

The CARBBIA kit bundles the thermostat, a plastic sleeve, and multiple gaskets so you can replace the entire thermostat assembly seal and seating components at once. Replacing these parts together reduces the risk of leaks and ensures proper thermostat operation.

• 1 x 160°F thermostat (compatible with Merc 808252 / 8M0109441).
• 1 x plastic sleeve (compatible with Merc 23‑806922) for correct thermostat seating.
• Multiple gaskets: cover gaskets and housing gasket to restore leak‑tight seals.
• Packaged to match Merc part 807252Q5 and GLM 13101 cross‑references.

How do I know this kit will install correctly and perform in a standard cooling system?

The thermostat temperature rating (160°F) and included sleeve are selected to match factory specifications for standard Mercruiser cooling setups, helping maintain the engine’s designed operating range. Use the kit when the original thermostat is sticking, when gaskets show wear, or whenever replacing the thermostat housing to ensure a complete seal.

• 160°F thermostat chosen for stock cooling applications—matches many OEM specs.
• Plastic sleeve ensures the thermostat sits properly and operates without distortion.
• Included gaskets replace worn seals and prevent coolant leaks around the housing and cover.

Are there compatibility caveats or things to check before ordering?

Confirm your engine’s model year and displacement and compare existing part numbers before purchasing; while this kit covers wide applications, some Sierra listings note a version without the plastic sleeve. Inspect your current thermostat housing and part references to ensure the best fit.

• Verify Merc part numbers on your engine (807252Q5 / 808252 equivalents) for exact interchangeability.
• Sierra part 18‑3647 is similar but may omit the plastic sleeve—check which you need.
• Intended for standard cooling systems; performance or aftermarket cooling setups could require different thermostats.

Who is this for: Boat owners, marine mechanics, and DIY enthusiasts replacing a thermostat assembly on 1987‑up Mercruiser GM V6 or V8 engines who want a complete kit that includes the thermostat, plastic sleeve, and the gaskets needed for a proper seal. If you need a single SKU that cross‑references common OEM numbers and restores factory‑like fit and function for standard cooling systems, this CARBBIA kit is a practical replacement option.