32-14358T + 32-44348T Twin-Engine 4-Inch Exhaust Service Kit · Fits MerCruiser center-rise 4-inch wet exhaust with 807166A3 shutters, Replaces 18-2746, 18-2748, 18-2732

32-14358T + 32-44348T Twin-Engine 4-Inch Exhaust Service Kit · Fits MerCruiser center-rise 4-inch wet exhaust with 807166A3 shutters, Replaces 18-2746, 18-2748, 18-2732

GHMarine twin-engine exhaust service kit for select center-rise 4-inch wet exhaust systems — two engines worth of upper and lower 4-inch bellows plus one 807166A3 offset-plate water-shutter pair. This is a GHMarine internal combination — there is no Mercury parent kit number for the full pack. 807166A3 is the shutter assembly only, not the parent number for four bellows.

Ships as 2 × lower 32-14358T + 2 × upper 32-44348T + 1 × 807166A3 shutter pair (2 shutters) + 8 stainless hose clamps. Confirm each engine's upper tube, lower tube, Y-pipe shutter style, and serial before you order.

Which kit is this?

This kit is for twin-engine boats that use center-rise 4-inch wet exhaust: each engine needs one upper bellow (riser to elbow), one lower bellow (elbow to Y-pipe), and an offset-plate shutter pair that matches 807166A3. Buying the twin pack covers both engines in one box.

It is not a factory Mercury multi-bellow parent kit, not a single-engine 1+1 pack (see GH 18BS001), and not a 2× lower-only pack (see GH 18BK001). If you only need shutters, see GH 17ST004 / 17ST005.

Signs yours is due

• Twin-engine boat: both engines share the same center-rise 4-inch layout — boots and 807166A3 offset shutters are due on the same haul-out.
• One engine already spit water from a Y-pipe shutter; the other engine's upper/lower boots are glazed — finish both engines in one kit.
• You confirmed oval offset-plate shutters (A3), not later rectangular A1 or manifold A2 — wrong shutter family voids this pack.
• Divert: single engine upper+lower only → GH 18BS001. Two lowers only → GH 18BK001. Shutters alone → GH 17ST004 / 17ST005.

Will it fit my drive?

This twin-engine combination is Compatible with select MerCruiser center-rise 4-inch wet exhaust layouts where each engine simultaneously uses: upper 32-44348T family, lower 32-14358T family, and Y-pipe shutters in the 807166A3 offset-plate family. Representative catalog band for the intersection is about 1987–1996 — years alone do not prove fit. Confirm engine/exhaust assembly, Y-pipe hole style, and serial for both engines.

*Representative intersection band from catalog evidence. Final fit = per-engine upper + lower + shutter style + SN/EPC — not Alpha/Bravo name or horsepower alone.

OEM & swap numbers

There is no OEM parent number for this full twin pack. Cross-refs below are for the three component families inside the box.

Wrong part? Read before you order

• NOT an OEM Mercury parent kit — 807166A3 is shutters only
• NOT for later rectangular-grommet shutters 807166A1 (GH 17ST002 / 17ST003)
• NOT for one-piece-manifold shutters 807166A2 (GH 17ST007 / 17ST008)
• NOT for 3-inch Y-pipe shutters 99370A2
• NOT for 3-inch / 3-to-4-inch bellows 32-90949T / 70981A3
• NOT a single-engine 1 upper + 1 lower pack — that is GH 18BS001
• NOT a 2× lower-only pack — that is GH 18BK001

What ships in the box

• 2 × Lower 4-inch exhaust bellows (32-14358T family)
• 2 × Upper 4-inch exhaust bellows (32-44348T family)
• 1 × Water shutter assembly 807166A3 (2 offset-plate shutters)
• 8 × Stainless hose clamps (one at each bellow end)

Often ordered with related SKUs

• Single-engine upper+lower only (no shutters) → GH 18BS001
• Two lower 32-14358T only → GH 18BK001
• 807166A3 shutters alone → GH 17ST004 / 17ST005
• Transom exhaust bellow (bell housing) → GH 17B1003

Install tips on the 4-inch wet exhaust path

Engine-bay / Y-pipe work. If you are not comfortable opening the wet exhaust path on both engines, use a marine shop. This kit is not a sterndrive bell-housing bellow job — do not assume bellows adhesive / expander for every joint.

1. Confirm both engines: upper 32-44348T path, lower 32-14358T path, and 807166A3 offset-plate Y-pipe shutters (not A1/A2).
2. Replace one engine at a time or stage parts so upper/lower/shutter pairs do not get swapped between engines.
3. Seat each bellow fully; clamp both ends; verify orientation and clearance to heat / moving parts.
4. Install the 807166A3 shutter pair per the Y-pipe hole style — offset-plate only.
5. Run and check for exhaust leaks, water spray, and normal temperature on both engines before returning the boat to service.

FAQ

Is 807166A3 the kit parent number?

No. 807166A3 is only the water-shutter pair (2 shutters). This GHMarine twin pack also includes two upper and two lower 4-inch bellows plus eight clamps. There is no Mercury parent number for the full combination.

Will this fit every twin-engine MerCruiser?

No. Both engines must use the center-rise 4-inch upper/lower bellow families and the 807166A3 offset-plate shutter style. Confirm each engine's parts diagram and serial — Alpha/Bravo labels alone do not prove fit.

I only have one engine to service — should I buy this?

Usually no. This box is sized for two engines (2 upper + 2 lower + 1 shutter pair). For one engine's upper+lower without shutters, see GH 18BS001. For shutters alone, see GH 17ST004 / 17ST005.

Is this the same as 807166A1 or 807166A2?

No. A1 is the later rectangular-grommet shutter family. A2 is the one-piece-manifold shutter family. This kit's shutters are the A3 offset-plate pair only.

What comes in the box?

Two lower 32-14358T bellows, two upper 32-44348T bellows, one 807166A3 shutter pair (2 shutters), and eight stainless clamps.

Do I need bellows adhesive and an expander?

Follow the service method for each joint. This is an engine-bay 4-inch wet-exhaust service kit, not the transom bell-housing exhaust bellow (GH 17B1003). Do not copy adhesive/expander steps from a sterndrive boot listing blindly.

Please note

Aftermarket replacement combination by GHMarine. Not an OEM Mercury parent kit. Not affiliated with engine manufacturers named above. "Compatible with", "Replaces", and cross-ref numbers identify component families — always confirm both engines' serial numbers, Y-pipe shutter style, and upper/lower part numbers before ordering.