3852742 Legacy Lower Exhaust Hose 3.5×4.25-Inch · Fits OMC Cobra select 1986–1991, Replaces 18-2781, 89230, 778066

3852742 Legacy Lower Exhaust Hose 3.5×4.25-Inch · Fits OMC Cobra select 1986–1991, Replaces 18-2781, 89230, 778066

GHMarine legacy lower exhaust hose for select OMC Cobra center-rise packages — OEM 3852742, about 3.5-inch I.D. × 4.25-inch long, without the later bump used on 3863450. Cross-refs 778066, 912376, 913592, 18-2781, 89230, 9-72801.

This page sells one legacy lower hose only. It is not the later bump lower 3863450 (GH 17B1013), not the upper 3852696 (GH 17B1011), and not a sterndrive seal bellow. Do not order by 89222 — that number tracks the later bump family, not this SKU.

Which hose is this?

It is the short lower exhaust hose / coupler on older OMC Cobra center-rise layouts that specify 3852742. Look at the old hose: no molded bump / bulge of the later 3863450 style.

It is not bump lower 3863450 / 18-2780-1 (GH 17B1013 / 17B2003), not upper 3852696 (GH 17B1011), not cone-clutch transom bellow 3850426 (GH 17B1010), and not the four-piece upper+lower pack (GH 17B4001).

Signs yours is due

• Late-1980s / early-1990s Cobra center-rise: the short lower hose (~3.5×4.25 in, no bump) is cracked, soft, or heat-glazed — stamped 3852742 / 18-2781 when readable.
• Soot or cooling-water drip at the lower engine-bay exhaust joint (not a transom seal leak and not the upper short hose position).
• Your old lower hose has no bump, but a catalog pushed 89222 / 3863450 — stop and match the physical shape before checkout.
• Divert: hose has the later bump → GH 17B1013. Upper short hose → GH 17B1011. Need both upper and lower packs → GH 17B4001.

Will it fit my drive?

This legacy lower hose is Compatible with select OMC Cobra center-rise packages that specify 3852742 (representative band about late 1986–1991, including select 2.3L / 4.3L / 5.0·5.8L / 5.7L rows — still confirm EPC). Original part number and no-bump shape decide fit — do not swap it with bump lower 3863450.

*Representative catalog band. Final fit = OEM 3852742 + no-bump shape on the old lower hose / EPC — not horsepower alone.

OEM & swap numbers

Primary OEM 3852742. Verified-style cross-refs for this no-bump lower: 18-2781, 89230, 9-72801, 778066 / 912376 / 913592.

Wrong part? Read before you order

• NOT bump lower 3863450 / 18-2780-1 (GH 17B1013)
• NOT upper short hose 3852696 (GH 17B1011)
• NOT cone-clutch transom bellow 3850426 (GH 17B1010)
• NOT four-piece upper+lower pack (GH 17B4001)
• NOT order-by 89222 alone
• NOT a sterndrive seal / gimbal-bearing kit

What ships in the box

• 1 × Legacy lower exhaust hose (3852742 family · no bump · ~3.5×4.25 in)
• Clamps when supplied — confirm against your package

Often ordered with related SKUs

• Upper short hose 3852696 → GH 17B1011
• Later bump lower 3863450 → GH 17B1013
• Bump lower 2-pack → GH 17B2003
• Upper×2 + lower×2 pack → GH 17B4001

Install tips in the engine bay

Engine-bay center-rise lower-hose work. Cold engine; disconnect battery; follow the OMC / Volvo Penta exhaust procedure for your assembly. Confirm the old hose has no bump before you install 3852742. Usually you do not pull the sterndrive for this short lower coupler — do not copy a full transom-kit adhesive / expander recipe blindly.

1. Confirm old hose is legacy lower 3852742 (~3.5×4.25 in, no bump) — not 3863450 and not upper 3852696.
2. Support the joint; loosen clamps; remove the old hose; clean mating tubes.
3. Seat the new hose fully without twist; place clamps on the clamp lands if supplied in your package.
4. Tighten to the service-manual specification for that assembly (no universal torque invented on this page).
5. Run and check for exhaust / water leaks at the lower joint before returning the boat to service.

FAQ

Is this the later bump lower hose?

No. 17B1012 is 3852742 without bump. The later bump lower is 3863450 (GH 17B1013).

Can I use 89222 to order this?

No. 89222 is treated here as a later bump-family pointer, not a verified main cross for 3852742. Match 3852742 / 18-2781 / 89230.

Is this the upper hose?

No. Upper short hose is 3852696 (GH 17B1011). This page is the legacy lower position only.

Is this a sterndrive seal bellow?

No. It is an engine-bay lower exhaust hose / coupler on select late-1980s to early-1990s OMC Cobra center-rise packages.

What comes in the box?

One 3852742 legacy lower hose and clamps when supplied (confirm against your package).

Do I pull the drive and use bellows adhesive?

Usually no for this short lower coupler. Follow the engine-bay hose method in your service manual — do not assume a pull-drive multi-boot kit procedure.

Please note

Aftermarket replacement by GHMarine. Not affiliated with engine manufacturers named above. "Compatible with", "Replaces", and cross-ref numbers identify the 3852742 no-bump legacy lower family — always confirm shape (no bump), EPC, and package contents before ordering.