UANOFCN Mercruiser Exhaust Bellow 18654A1 for Alpha I Gen II — Direct-Fit, Watertight Vibration Dampening

UANOFCN 18654A1 Exhaust Bellow is a direct-fit replacement for Mercruiser Alpha 1 Gen II stern drives, restoring a watertight, vibration-dampening connection between the exhaust elbow and transom outlet.

When your stern drive shows exhaust leaks, unusual noises, or signs of corrosion at the bellow connection, this replacement part reinstalls the flexible joint that carries engine exhaust out the transom. Designed as a high-quality aftermarket option, the UANOFCN bellow fits a broad range of Mercruiser models and year ranges and is manufactured to match the original fit and function so you can return to reliable on-water performance without modifying the drive.

Which Mercruiser models and years does this bellow fit?

This exhaust bellow is compatible with many early and later Mercruiser stern drives. It replaces OEM part numbers like 18654A1 and cross-references several legacy numbers, covering multiple drive families and specific engine models from the late 1970s through later Alpha generations.

• Compatible with Alpha I Gen II drives and related Alpha, Bravo and Blackhawk units
• Fits models listed as #1, R, MR, TRS and similar drive codes
• Also suitable for Mercruiser 120/140 (1978–1982), 165 (1978–1981), 260 (1978–1982) and 470 (1978–1982)

How does this replacement bellow restore exhaust performance?

The bellow re-establishes a sealed, flexible connection that prevents exhaust gases and water intrusion at the transom. A new bellow reduces vibration, stops exhaust leaks that cause backpressure or noise, and protects the drive and hull from exhaust-related corrosion.

• Restores watertight seal between elbow and outlet
• Dampens vibration to reduce noise and wear
• Prevents corrosive exhaust leakage onto drive components

What quality and fit expectations should I have for this aftermarket part?

UANOFCN supplies this bellow as a brand-new, high-quality aftermarket replacement produced with matched dimensions for direct installation. The product is inspected in cooperation with local workshops to ensure consistent fit and durable materials comparable to OEM performance.

• 100% new unit manufactured to OEM-style specifications
• Quality checks performed through partnered local workshop
• Designed for direct swap with original 18654A1-style components

How do I install the exhaust bellow and what should I check during replacement?

Installation requires access to the lower unit and exhaust elbow—standard mechanical skills and basic tools are sufficient for a competent DIYer. Inspect surrounding clamps, gaskets and the transom outlet for wear; replace any compromised hardware to ensure a proper seal and long service life.

• Remove old bellow, clean mating surfaces before fitting new part
• Use new clamps or torque existing clamps to manufacturer specs
• Confirm no exhaust leaks after installation at idle and load

Who is this for: Boat owners, mechanics and marine service shops working on Mercruiser stern drives that need a dependable replacement for a failing exhaust bellow. It's ideal for vessels using Alpha I Gen II and related drives, owners restoring older Mercruiser engines from the late 1970s and early 1980s, and anyone seeking an aftermarket part that closely matches OEM fit and function without extensive modification.