This exhaust bellows is a flexible spare part for MerCruiser 170 and 488 engine variants. The bellows corresponds to original reference 70981A3 and is used as a connection in the engine's exhaust system.
The stepped design connects exhaust components with different diameters. The bellows is mounted between the exhaust elbow and the rest of the engine's exhaust pipe or system, where its flexible construction absorbs movement between the components.
The bellows has a height of 122 mm, an upper diameter of 78 mm, and a lower diameter of 100 mm. The nominal inner diameter ranges from 3″ to 4″, corresponding to approximately 76–101 mm. The designation 170/488 is a model indicator and should not be understood as a power output range.
Compatible engine models
Directly documented for MerCruiser 170 and 488R. Original reference 70981A3 is also used on selected older MerCruiser models, including 470, 485, 898, 228, 250, 260, 280, 330, and Ford 233. The specific application depends on the engine serial number and exhaust configuration.
Replaces OEM numbers
The primary original reference is 70981A3. The previous number 70981 has been replaced by 70981A3. Documented cross-references include CEF 500523, Sierra 18-2762, and GLM 89070.
Depending on the engine and configuration, the exhaust assembly may use a small hose clamp with reference 54-33683 or 54-815504456 and a large hose clamp with reference 54-31765 or 54-815504372. These references identify mounting-related components and do not indicate that clamps are included.
Always check the engine/drive model, serial number, exhaust configuration, and original part number before purchasing.
Key featuresFlexible exhaust bellows for MerCruiser
Model designation: 170/488 HP
Original reference: 70981A3
Previous reference: 70981
Stepped connection from 3″ to 4″
Height: 122 mm
Upper diameter: 78 mm
Lower diameter: 100 mm
Sales unit: 1 pc.
