861189A1 Mercruiser AdaptorTBI 5.0 - 5.7 GM | Genuine Used Part

🔧 Product Description

Genuine MerCruiser TBI Adapter Assembly - Part Number: 861189A1

A genuine used throttle-body injection adapter for GM-based MerCruiser 5.0L and 5.7L EFI V8 marine engines.

The adapter mounts between the intake manifold and the two-barrel throttle-body injection unit. It provides the correct bolt pattern, airflow transition and sealing surfaces required to install the MerCruiser TBI assembly on the Vortec intake manifold.

⚙️ Key Features

• Genuine Mercury MerCruiser TBI adapter
• Correct part number 861189A1
• Designed for GM 5.0L and 5.7L V8 engines
• Two-barrel throttle-body mounting configuration
• Obsolete genuine OEM component

🚤 Compatibility

Commonly used on

• MerCruiser 5.0L EFI / TBI engines
• MerCruiser 5.7L EFI / TBI engines
• GM-based marine V8 engines using the 860100-series intake
• Early electronic fuel-injection sterndrive and inboard installations

Typically suits

• Engine models:
• MerCruiser 5.0 EFI
• MerCruiser 5.7 EFI
• MerCruiser GM 305 and 350 V8 TBI engines
• Selected late-1990s and early-2000s Alpha, Bravo and inboard applications
• Engine Size: 5.0L and 5.7L V8
• Fuel System: Two-barrel throttle-body injection
• Year Range: Approximately late 1990s - early 2000s
• Fitment Requirement: Confirm throttle-body bore, bolt pattern, manifold and linkage clearance

🔌 Function

The adapter transitions airflow from the throttle body into the intake manifold and provides the mounting and sealing interface for the TBI unit.

⚠️ Common Signs of Failure

• Vacuum leak around the adapter
• Cracked or corroded casting
• Warped gasket surface
• Damaged throttle-body mounting threads
• Incorrect throttle-body alignment

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 861189A1 final verified Mercury MerCruiser adapter reference
• Part is no longer produced
• No confirmed direct supersession

OEM / Related Numbers

• 861189A1
• Mercury UPC 745061448575
• MerCruiser TBI adapter assembly
• 860100A1 related two-barrel Vortec intake manifold
• GM 5.0L / 305 CID EFI marine engine
• GM 5.7L / 350 CID EFI marine engine
• Matching throttle-body gasket and adapter gasket required

Aftermarket / Verified Equivalents

• No direct aftermarket adapter verified
• Used genuine 861189A1 assemblies are the closest replacement
• Automotive TBI adapters are not automatically suitable because marine bolt patterns, height and sealing provisions may differ

📦 Condition

• Genuine used part
• Removed from running engine where applicable
• In good working condition unless otherwise stated