3863450 Lower Exhaust Hose with Bump 2-Pack 3.5×5.5-Inch · Fits OMC / Volvo Penta center-rise select, Replaces 18-2780-1, 89222

3863450 Lower Exhaust Hose with Bump 2-Pack 3.5×5.5-Inch · Fits OMC / Volvo Penta center-rise select, Replaces 18-2780-1, 89222

GHMarine bump lower hose 2-pack for select OMC / Volvo Penta center-rise packages that call for two of the same lower hose — OEM 3863450 × 2, each about 3.5-inch I.D. × 5.5-inch with the molded bump. Per-hose cross-refs 18-2780 / 18-2780-1, 89222, 9-72800 / 9-72814, REC3863450. Legacy 3852741 only when your EPC supersession chain lists it. There is no factory kit OEM for this CSKU — parent identity is the GH pair only.

This page sells two bump lower hoses. Need only one → GH 17B1013 (3863450 ×1). It is not the upper short-hose pair (GH 17B2004 · 3852696 ×2), not the four-piece upper+lower pack (GH 17B4001), and not the older no-bump lower 3852742 (GH 17B1012).

Which pack is this?

It is a pair of later lower exhaust hoses / couplers for center-rise packages that specify 3863450 on both banks or both paths. Each hose carries the molded bump — if your old lowers are smooth with no bump, you are on the wrong page.

It is not a single hose (GH 17B1013), not upper pair 3852696 ×2 (GH 17B2004), not legacy no-bump lower 3852742 / 18-2781 (GH 17B1012), not drive / clutch-dog bellow 914036, and not a sterndrive seal kit.

Signs you need the pair

• Both center-rise lower joints (port and starboard / both banks) use the same ~3.5×5.5 in bump hose stamped 3863450 / 18-2780-1 / 89222 — and both are cracked, soft, or heat-glazed.
• You already confirmed one hose is 3863450 with bump, and the second path uses the identical part number — buy the pair once instead of two singles.
• Soot or cooling-water drip at both lower engine-bay exhaust joints (not a transom seal leak and not the upper short-hose position).
• Divert: only one hose → GH 17B1013. No bump → GH 17B1012. Upper short hoses ×2 → GH 17B2004. Upper×2 + lower×2 → GH 17B4001.

Will it fit my drive?

This bump lower pair is Compatible with select OMC / Volvo Penta center-rise packages that specify 3863450 on both lower paths — representative bands include Ford 5.0 / 5.8L about 1991 & up and late center-rise / SX rows about 1994–1998. Original part number and bump shape decide fit — do not order from a vague "1994 & up" tag without EPC proof.

*Representative catalog bands. Final fit = OEM 3863450 + bump shape on both old lower hoses / EPC — not horsepower alone. If only one path needs replacement, order GH 17B1013.

OEM & swap numbers

Primary OEM per hose 3863450; this CSKU ships qty 2. Cross-refs for each bump lower: 18-2780 / 18-2780-1, 89222, 9-72800 / 9-72814, REC3863450.

Wrong part? Read before you order

• NOT a single bump lower — that is GH 17B1013 (3863450 ×1)
• NOT upper short-hose pair 3852696 ×2 (GH 17B2004)
• NOT four-piece upper+lower pack — that is GH 17B4001
• NOT legacy no-bump lower 3852742 / 18-2781 (GH 17B1012)
• NOT clutch-dog / drive bellow 914036
• NOT cone-clutch transom bellow 3850426 (GH 17B1010)
• NOT a sterndrive seal / gimbal-bearing kit

What ships in the box

• 2 × Lower exhaust hose with bump (3863450 family · ~3.5×5.5 in each)
• Clamps when supplied — confirm count against your package (do not assume one clamp set per hose unless the carton shows it)

Gallery note: some product photos show a single hose for shape/size reference. The sold quantity is two bump lowers — verify both hoses in the carton before install.

Often ordered with related SKUs

• Single bump lower (3863450 ×1) → GH 17B1013
• Upper short hose ×2 → GH 17B2004
• Upper×2 + lower×2 pack → GH 17B4001
• Legacy no-bump lower → GH 17B1012

Install tips for both banks

Engine-bay center-rise lower-hose work on both paths. Cold engine; disconnect battery; follow the OMC / Volvo Penta exhaust procedure for your assembly. Confirm both old hoses have the bump before you install 3863450 ×2. Usually you do not pull the sterndrive for these short lower couplers — do not copy a full transom-kit adhesive / expander recipe blindly.

1. Confirm both old hoses are bump lowers 3863450 (~3.5×5.5 in) — not 3852742 and not upper 3852696.
2. Replace one bank at a time: support the joint; loosen clamps; remove the old hose; clean mating tubes.
3. Seat each new hose fully with the bump oriented as on the old part; place clamps on the clamp lands if supplied.
4. Repeat on the second path with the second hose from this pack.
5. Tighten to the service-manual specification for that assembly (no universal torque invented on this page).
6. Run and check for exhaust / water leaks at both lower joints before returning the boat to service.

FAQ

How many hoses are in this box?

Two. 17B2003 is 3863450 ×2 (bump lowers). For one hose only, see GH 17B1013.

Does each hose have a bump?

Yes. Both are 3863450 with the molded bump. If your old hoses have no bump, see GH 17B1012 (3852742).

Is this the same as the upper hose pair?

No. Upper short hoses are 3852696 ×2 (GH 17B2004). This pack is lower bump hoses only.

Can I order from a vague 1994 & up year tag?

No. Confirm 3863450 + bump on both old hoses or EPC (representative bands ~1991+ Ford / ~1994–1998 late center-rise).

Do photos show two hoses?

Some gallery shots are single-hose shape references. The carton quantity is two — count both before install.

Do I pull the drive and use bellows adhesive?

Usually no for these short lower couplers. 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 3863450 bump lower family — always confirm bump shape, EPC, carton quantity (2), and package contents before ordering.