Exhaust Manifold Bellow – Fits MerCruiser 120/140/3.0L 4-Cylinder & Various V6/V8 Models (Replaces 70981A3, 90949T)
Exhaust Manifold Bellow – Fits MerCruiser 120/140/3.0L 4-Cylinder & Various V6/V8 Models (Replaces 70981A3, 90949T) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Exhaust Manifold Bellow – Fits MerCruiser 120/140/3.0L 4-Cylinder &...
Exhaust Manifold Bellow – Fits MerCruiser 120/140/3.0L 4-Cylinder & Various V6/V8 Models (Replaces 70981A3, 90949T) is backordered and will ship as soon as it is back in stock.
Product Details
This Exhaust Manifold Bellow 70981A3 – Fits MerCruiser 120/140/3.0L 4-Cylinder & Various V6/V8 Models is a crucial component for connecting the upper exhaust manifold to the elbow. It is designed specifically for MerCruiser 4-cylinder, V6, and V8 engines with wet joint exhaust systems manufactured between 1982 and 2002.
This part serves as a direct replacement for MerCruiser 70981A3, Sierra 18-2762, GLM 89070, Mallory 9-72808, Quicksilver 70981A3, and others.
- Connects the 3-inch center mounted riser to the 4-inch exhaust elbow.
- Constructed from durable CR (Chloroprene) rubber for longevity in marine environments.
- Designed for use in "wet joint" exhaust systems common in pre-2002 MerCruiser models.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| MerCruiser | 70981A3 |
| MerCruiser | 90949T |
| MerCruiser | 27-92720 |
| Quicksilver | 70981A3 |
| Sierra | 18-2762 |
| GLM | 89070 |
| Mallory | 9-72808 |
| GHmarine | 70981A3 |
| NorthBoat | 70981A3 |
| SoxaMarine | 70981A3 |
Engine & Model Compatibility
Confirm your engine model and year in the table below.
This bellow is designed for MerCruiser engines utilizing a "wet joint" exhaust system, typically found in models from 1982 to 2002.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 120/140 - Inline 4 | 120–140 | 4-Stroke | 1982–1995 | 70981A3 | For 153/181 CID, wet joint models |
| MerCruiser | 2.5L/3.0L | 120–140 | 4-Stroke | 1987–1995 | 70981A3 | Models with wet joint exhaust |
| MerCruiser | 175-205 - V6 | 175–205 | 4-Stroke | 1983–2002 | 70981A3 | GM 229/262 CID, wet joint models |
| MerCruiser | 200-320 - V8 S.B. | 200–320 | 4-Stroke | 1983–2002 | 70981A3 | GM 305/350/377 CID, wet joint models |
| MerCruiser | 330-370 - V8 B.B. | 330–370 | 4-Stroke | 1981–2002 | 70981A3 | GM 454/502 CID, wet joint models |
| MerCruiser | 470/485 | 170–190 | 4-Stroke | 1983–1989 | 70981A3 | 224 CID, wet joint models |
| MerCruiser | 898, 228, 250, 260, 280 | Varies | 4-Stroke | 1983–2002 | 70981A3 | Various models with wet joint exhaust |
Technical Specs
- Product Type
- Exhaust Bellow / Exhaust Boot
- Installation
- Upper Exhaust Manifold to Elbow Connection
- Connection
- 3-inch Center Mounted Riser to 4-inch Elbow
- Housing Material
- CR (Chloroprene) Rubber Bellow
- Housing Color
- Black
- Dimensions
- 3-inch to 4-inch diameter transition
- Fitting Type
- Hose with Clamp Connection
- Warranty
- Varies by manufacturer (1 Year for GHmarine)
- Other Technical Attributes
- Used with 2-piece exhaust elbow in wet joint applications
What’s in the Box
- 1 x Exhaust Bellow/Boot (70981A3)
Installation Notes
- Ensure the engine is off and has cooled completely. Disconnect the boat's battery.
- Drain the exhaust system to prevent water spills.
- Locate the exhaust bellow connecting the manifold riser to the exhaust elbow.
- Loosen and remove the two hose clamps securing the old bellow.
- Carefully slide the old bellow off both the riser and elbow connections.
- Thoroughly clean the connection surfaces on the riser and elbow to ensure a proper seal.
- Slide the new bellow into position, ensuring it is fully seated on both ends.
- Position the new hose clamps over the bellow and tighten them securely according to manufacturer specifications. Do not overtighten.
- Reconnect the battery, start the engine, and carefully inspect for any exhaust or water leaks around the new bellow.
Troubleshooting & FAQ
How can I confirm this bellow fits my specific engine?
First, check your engine model and year against the compatibility table above. This bellow is designed for MerCruiser models from 1982–2002 with a "wet joint" exhaust system. If your engine is newer than 2002, it likely uses a "dry joint" system and this part will not fit.
What is the difference between a "wet joint" and "dry joint" exhaust?
A "wet joint" exhaust system allows cooling water to pass through the gasket area between the manifold and elbow. A "dry joint" system, introduced by MerCruiser after 2002, keeps cooling water separate from the exhaust gas passage at this joint. This bellow is only for wet joint applications.
What are the signs of a failing exhaust bellow?
Common symptoms include visible cracks or perishing on the rubber, water leaking from the joint between the manifold and elbow (especially when the engine is running), rust stains in this area, or the smell of exhaust fumes in the engine compartment.
How often should this part be replaced?
It is recommended to inspect the exhaust bellows annually for signs of wear, cracking, or stiffness. Replacement should be part of routine exhaust system maintenance every 5-7 years, or immediately if any damage or leaking is detected.
Is this an OEM part or an aftermarket one?
This listing is for an aftermarket replacement part, not an original equipment manufacturer (OEM) component. It has been engineered to meet or exceed OEM specifications using comparable materials and is manufactured in an ISO 9002 certified facility with batch inspections to ensure quality.
What are the shipping costs and delivery times?
We offer fast worldwide shipping, with typical transit times of 5–15 days for most regions. Standard shipping is free. Expedited shipping options, if available for your location, will be presented at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard return window for items that are unused and in their original packaging. Please see our full policy page or contact us for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement component, not an OEM part.
- Professional installation is highly recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world marine conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
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