Upper Exhaust Bellows – Fits MerCruiser 3.0-8.2L (Replaces 70981A3, 18-2762)
Upper Exhaust Bellows – Fits MerCruiser 3.0-8.2L (Replaces 70981A3, 18-2762) is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Upper Exhaust Bellows – Fits MerCruiser 3.0-8.2L (Replaces 70981A3,...
Upper Exhaust Bellows – Fits MerCruiser 3.0-8.2L (Replaces 70981A3, 18-2762) is backordered and will ship as soon as it is back in stock.
Product Details
This replacement Upper Exhaust Bellows fits a wide range of MerCruiser sterndrive engines from 1980 and later. It is designed for models including the 165/170/3.7L series (1980–1989), V6 229/262 engines (1983+), and various Chevy-based V8s like the 305, 350, 377, 454, and 502 (1981+).
This part provides a direct interchange for MerCruiser 70981A3, Sierra 18-2762, GLM 89070, and Mallory Marine 9-72808.
- Installs on 3-inch 15-degree center mounted risers with a 4-inch elbow.
- Constructed from durable rubber with reinforcement for longevity.
- Simple bolt-on installation with included clamps.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| MerCruiser | 70981A3 |
| Sierra | 18-2762 |
| GLM | 89070 |
| Mallory Marine | 9-72808 |
Engine & Model Compatibility
Confirm your engine model and year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 165/170/3.7L/180/190/470/485/488 | Various | 4-Stroke | 1980–1989 | 70981A3 | Manifold applications |
| MerCruiser | 3.0L | 130-140 | 4-Stroke | 1983 and up | 70981A3 | |
| MerCruiser | 5.0L (305 CID) | 190-220 | 4-Stroke | 1983 and up | 70981A3 | Chevy V8 |
| MerCruiser | 5.7L (350 CID) | 220-300 | 4-Stroke | 1983 and up | 70981A3 | Chevy V8 |
| MerCruiser | 6.2L (377 CID) | 320+ | 4-Stroke | 1983 and up | 70981A3 | Chevy V8 |
| MerCruiser | 7.4L (454 CID) | 310-330 | 4-Stroke | 1981 and up | 70981A3 | Big Block |
| MerCruiser | 8.2L (502 CID) | 375-425 | 4-Stroke | 1981 and up | 70981A3 | Big Block |
| MerCruiser | V6 229/262 CID | Various | 4-Stroke | 1983 and up | 70981A3 | V6 engines |
Technical Specs
- Product Type
- Upper Exhaust Bellows
- Installation
- Bolt-On with Clamps
- Material
- Rubber with Reinforcement
- Connection
- 3-inch to 4-inch
- Dimensions
- Fits 3-inch 15-degree center mounted risers with 4-inch elbow
- Weight
- 198 g (0.44 lb)
What’s in the Box
- 1 x Upper Exhaust Bellows
- 2 x Stainless Steel Clamps
Installation Notes
- Disconnect the boat's battery for safety.
- Gain clear access to the engine's exhaust riser and elbow assembly.
- Carefully loosen and remove the clamps securing the old exhaust bellows.
- Remove the old, worn bellows. Note its orientation.
- Thoroughly clean the mating surfaces on the riser and elbow, removing any old sealant or debris.
- Fit the new bellows into position, ensuring it is properly seated on both ends.
- Secure the new bellows using the provided stainless steel clamps. Tighten them firmly but do not overtighten.
- Once installed, run the engine and check for any signs of exhaust or water leaks around the new bellows.
- Reconnect the battery if all checks are clear.
Troubleshooting & FAQ
How do I know if this bellows will fit my specific engine model?
The best way is to verify your engine model and year against the compatibility chart above. You can also cross-reference your existing part number with those listed in the Part Number Matrix.
What are the common signs of a failing exhaust bellows?
Symptoms of a worn or cracked exhaust bellows include water leaking into the bilge, a noticeable exhaust odor in the engine bay, or engine overheating. A physical inspection showing cracks, splits, or brittleness in the rubber also indicates it's time for a replacement.
How often should I replace my exhaust bellows?
It is recommended to inspect exhaust bellows annually for signs of wear, such as cracking or hardening. A general replacement interval is every 3-5 years, or immediately if any damage is found, especially for boats used in saltwater.
Does this kit include the necessary clamps for installation?
Yes, this kit includes two stainless steel clamps required for securing the bellows to the riser and elbow.
What's the difference between an upper and lower exhaust bellows?
This is an upper exhaust bellows, which connects the exhaust riser to the exhaust elbow on many MerCruiser models. The lower bellows (part of the transom assembly) connects the bell housing to the gimbal housing. Ensure you are ordering the correct part for your needs.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials and manufactured in an ISO 9001 certified facility, with batch-inspections for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact our support with your order details. Returns are accepted within our standard window for unused items in original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part. 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 recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or quality control.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
