Sierra 18-2141 Engine Mount Bolt Kit for Mercruiser Stern Drive, Replaces 10-97934A1

The Sierra 18-2141 Engine Mount Bolt Kit is a stainless steel hardware set built to secure the engine mount on Mercruiser stern drive installations. The kit contains the three fasteners needed for a complete mount attachment: a washer, a lock nut, and a motor mount bolt, so you are not stuck trying to source individual hardware pieces separately when a mount bolt is worn, corroded, or missing. Each piece is made from stainless steel with a machined finish and a hex head style, using 1/2-13 UNC right hand threading that is fully threaded along its length. Sierra manufactures this kit to meet or exceed the original equipment part it replaces, and it interchanges directly with GLM 21080 and Mercury Marine 10-97934A1, making it a straightforward drop-in replacement for stern drive engine mount service. Because engine mount hardware carries significant load and vibration during operation, using correctly graded, corrosion-resistant fasteners like this kit helps maintain a secure engine mount connection rather than reusing stretched or rusted original hardware. This kit is sold as a matched set of three pieces so the washer, lock nut, and bolt are sized correctly to work together.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2141
• Product Name: Engine Mount Bolt Kit
• Material: Stainless Steel
• Size Name: 1/2-13 UNC
• Thread Type: UNC
• Thread Style: Right Hand
• Thread Coverage: Fully Threaded
• Thread Class: 1A
• Fastener Type: Hexagon Bolt
• Head Style: Hex
• Grade Rating: Grade 10.9
• Exterior Finish: Machined
• Color: White
• Number of Pieces: 3
• Included Components: 18-0681 washer, 18-3728 lock nut, 18-3729 motor mount bolt
• Weight: 0.44 pounds
• UPC: 808282257705

Fitment

• Mercruiser stern drive engine mount applications

Replaces (OEM)

• GLM 21080
• Mercury Marine 10-97934A1

Frequently Asked Questions

What is included in the Sierra 18-2141 Engine Mount Bolt Kit? The kit contains three pieces: one 18-0681 washer, one 18-3728 lock nut, and one 18-3729 motor mount bolt, giving you the complete fastener set for one engine mount point.

What does the Sierra 18-2141 Engine Mount Bolt Kit replace? It interchanges with GLM 21080 and Mercury Marine 10-97934A1, so either of those part numbers can be used to identify the correct replacement kit.

What size threads does the 18-2141 bolt use? The motor mount bolt in this kit uses 1/2-13 UNC right hand threading that is fully threaded along its length.

What material is the Sierra 18-2141 kit made from? All three pieces in this kit are made from stainless steel with a machined finish, which resists corrosion in a marine environment.

What grade rating does the 18-2141 hardware carry? The bolt and lock nut in the 18-2141 kit are rated Grade 10.9, a hardened fastener grade suited to the load an engine mount bolt carries.

Does the Sierra 18-2141 fit Mercruiser stern drives? Yes, this bolt kit is designed for Mercruiser stern drive engine mount applications and interchanges with GLM 21080 and Mercury Marine 10-97934A1.

How much does the 18-2141 Engine Mount Bolt Kit weigh? The complete three-piece kit weighs 0.44 pounds.

Is the 18-2141 kit genuine Sierra hardware or a generic substitute? It is manufactured by Sierra, which states this part meets or exceeds the original equipment part it replaces rather than being a generic substitute.

Can I buy just the bolt or just the lock nut instead of the full kit? The 18-2141 is sold as a matched three-piece kit consisting of the 18-0681 washer, 18-3728 lock nut, and 18-3729 bolt together.

What head style does the 18-2141 motor mount bolt have? The bolt uses a hex head style, consistent with standard hex fastener installation using a wrench or socket.