2 × 32-14358T 4″ Riser Pair Kit for MerCruiser Lower Exhaust Boot

32-14358T Lower Exhaust Boot 2-Pack — Compatible with MerCruiser Center-Rise 4″ Oval Riser (2× Same Boot)

GHMarine ships two identical 4-inch oval lower exhaust boots — the rubber at the center riser elbow-to-Y-pipe joint inside the engine bay. Parts books call it a lower tube or exhaust boot; yard crews often say riser bellow — same piece, two in the carton.

Built for twin-bank or matched-pair service: each riser leg you refresh gets one boot. Running a single replacement point? Use GHMarine 17B1001 (one boot). This is not the transom bell-housing kit, not the upper 32-44348T, and not the 18BS002 Y-pipe/shutter bundle.

Clamp-on riser work in the hatch — hose clamps when shown in photos. Bellows adhesive is for 17B1003 territory, not this lower oval boot.

Lower oval boot — not upper, not bell, not full kit

This 2-pack is the in-hull 4″ lower oval on the center-rise path — not the inner transom upper (32-44348T → 17B1002 / 17B2002), not the big transom wet boot (8M0124227 → 17B1003), and not the 3″ lower (32-90949T → 24B1052).

Read the stamp on each removed boot, confirm 4″ oval at the riser joint, and count how many legs you are fixing. Carton qty 2 does not mean stack two on one pipe.

When to replace one riser boot vs both lowers

·       Ticking or louder exhaust under the hatch at idle — cracks at the 4″ riser elbow-to-Y-pipe boot show up as sound before you see a big leak. On twins, compare port and starboard riser paths.

·       Black soot wetting the rubber or flanges at the center riser — trace the in-hull 4″ path first. Staining at the transom outside usually means bell boot (17B1003); U-joint Gen II → 17B1007; Gen I →17B1004; not this lower oval boot.

·       Why buy two when only one looks bad? Matched-age twin banks or a planned manifold service often needs both lowers — this kit avoids a second order when the mate turns soft two weeks later.

·       Burnt-rubber smell after an overheat — glazed or hardened oval boot at the riser should be replaced even if the clamp still holds.

·       Spring opener checklist: split ribs, rusty band screws, oval boot that no longer springs back — budget two lowers if both riser legs show the same age.

Serial & diagram check — each bank counts

HP alone will not pick the boot — serial, diagram row, and molded 14358T-family stamp do. Core前台 years below; newer drives may differ — always match the exploded view.

Application	Years	Serial / check point	OEM ref	Notes
MerCruiser Alpha One Gen I / II	1983–1996	Gen I: S/N 06225577 thru 0D469858; Gen II: 0D469859 and up	32-14358T	4″ oval lower boot on center-rise path — kit = qty 2 for twin-bank refresh
MerCruiser Bravo One / Two / Three	1988–1996	Bravo SN 0B664190 and up — confirm Where-Used before order	32-14358T	Large-block Bravo still uses 4″ oval lower family on many MPI setups
MerCruiser MCM 4.3 / 5.0 / 5.7 / 6.2L V8	1982–1996	Two-piece manifold + 4″ Y-pipe context; match stamp on removed boot	32-14358T	Typical 175–430 HP center-rise exhaust — not carb-only 3″ paths
MerCruiser R / MR / MC-1 transition	1982–1990	Pre-Alpha oval transom 4″ exhaust — verify diagram row	32-14358T	Older oval-shape lower boot before Alpha Gen II cutover

 

Stamps & swap numbers (both boots share one family)

Factory IDs include 32-14358T, 32-14358001, and legacy 32-14358. Common swap refs: 18-2746, 89130, 9-72811.

Type	Part Number	Notes
OEM	32-14358T	Current 4″ oval lower exhaust boot (×2 in this kit)
OEM	32-14358001	Catalog variant — same lower tube family
OEM	32-14358	Legacy short-form numbering — interchangeable
OEM ref	31-14358001	Alternate listing number in older catalogs
Cross-ref	18-2746	Swap number — functionally replaces 32-14358T
Cross-ref	89130	Swap number — functionally replaces 32-14358T
Cross-ref	9-72811	Swap number — functionally replaces 32-14358T
Cross-ref	REC32-14358001	Catalog-style ID for the lower boot line

 

Checkout guard — location, diameter, and carton count

The center-rise exhaust rubber map is crowded — confirm all three before buy:

·       One engine, one riser boot — order GHMarine 17B1001 (qty 1). This carton is two identical lowers.

·       Not the 4″ upper at the inner transom plate — GHMarine 17B1002 single or 17B2002 upper pair (32-44348T).

·       Not the transom bell-housing wet boot 8M0124227 — GHMarine 17B1003; drive-off adhesive job.

·       Not the 3″ lower leg 32-90949T — GHMarine 24B1052; smaller diameter and different path.

·       Not the full Y-pipe / shutter / upper service kit — GHMarine 18BS002 (807166A3 family).

·       Not the water shutter flapper alone — GHMarine 18BS001 (807166A1). Rubber boot only here.

·       Not U-joint (Gen II / 816431A1 → GHMarine 17B1007; Gen I / 60932A4 → 17B1004) or shift bellows — GHMarine 17B1005.

Two-boot kit — carton contents

·       2 × 4″ oval lower exhaust boots (32-14358T family)

·       Hose clamps when shown in product photos

·       Not included: Y-pipe, shutter, upper tube, bell boot, U-joint rubbers, adhesive, expander tool

Often ordered with adjacent exhaust rubbers

·       Upper pair at inner transom — GHMarine 17B2002 (32-44348T ×2) when both uppers are due on a twin refresh.

·       Single lower spare — GHMarine 17B1001 if only one riser boot failed.

·       Transom bell boot — GHMarine 17B1003 per drive (8M0124227 family) — separate SKU, adhesive job.

·       Full Y-pipe / shutter service kit — GHMarine 18BS002 when the metal kit is what you need, not rubber-only.

·       Many owners renew clamps and all wet-exhaust rubbers while the hatch is open.

Riser install — clamp-on lower oval (repeat per leg)

Typical shop sequence: work with cold exhaust in the engine bay; drive stays on. You may need elbow or Y-pipe access — not a transom pull. Repeat for the second riser leg when using both boots from this kit.

Tools & prep

·       Band clamps (included when shown) · driver for clamp screws

·       Wire brush for riser stub and Y-pipe spigot on each leg

·       Soapy water — slides stiff oval rubber; keep petroleum grease off the exhaust path

Per-leg steps

1. Loosen hose clamps; free the old oval boot from the riser elbow and Y-pipe. Cut away if rust-bonded.

2. Brush stubs bright; wipe dry. Warm stiff replacements in hot tap water if needed.

3. Place clamps on the new boot first; seat fully on both stubs; tighten evenly so each band bites metal, not just rubber ribs.

4. Idle test on muffs; listen for tick or hiss at the riser joint. Re-snug clamps after the first hot run.

Transom bell boot (17B1003) uses adhesive / expander 91-45497A1 — different location and different SKU from this riser lower 2-pack.

FAQ — twin qty & riser fit

Single sterndrive — should I buy this 2-pack?

Usually no — one center-rise exhaust path needs one lower boot at the riser. Order GHMarine 17B1001 (single). 18BK001 is for two identical 32-14358T boots in one carton.

Twin engines or two riser legs — one boot each?

Yes — one 4″ oval lower per engine bank / riser leg you are refreshing. Never stack two boots on one joint. This kit ships qty 2 for qty 2 replacement points.

Same rubber as 17B1001?

Same molded 4″ oval lower at the elbow-to-Y-pipe joint — only carton count changes. 17B1001 = 1 boot; 18BK001 = 2 boots.

Is this the upper tube 32-44348T?

No — 44348T is the inner transom upper (17B1002 / 17B2002). This SKU is the lower 14358T family at the center riser.

Will the 3″ lower 32-90949T work instead?

No — 90949T is a 3″ path. Measure your removed boot: this kit is 4″ oval lower only.

Glue, expander, or pull the drive?

Typically a clamp-on engine-bay job at the riser — clean stubs, soap-and-water slide, tighten bands. Bellows adhesive and expander 91-45497A1 are for transom bell work (17B1003).

What is in the carton?

Two lower exhaust boots (32-14358T family) plus hose clamps when shown in photos. No Y-pipe, shutter, upper tube, bell boot, or U-joint rubbers.

Please note

Aftermarket replacement — not made or sponsored by engine OEMs referenced above. "Compatible with", "Replaces", and interchange numbers describe functional fit only. Confirm serial and diagram row on each engine bank before launch.