Exhaust Riser Screw – Fits MerCruiser 4.3L 5.0L 5.7L 6.2L Alpha Bravo (Replaces 865982077, 10-865982077)

Product Details

This Exhaust Riser Screw is engineered for MerCruiser sterndrive and inboard engines, including 4.3L, 5.0L, 5.7L, and 6.2L applications with Alpha and Bravo drive configurations. Compatible across a wide range of engine models—from 350 MAG MPI to 383 MAG Stroker and MX 6.2L MPI variants—this screw ensures secure exhaust riser mounting in demanding marine environments.

Designed as a direct replacement for MerCruiser OEM numbers 865982077 and 10-865982077, providing reliable interchange for original equipment.

• Thread specification: .375–16 × 10.500 inches
• Fits both Alpha and Bravo sterndrive systems, plus select inboard configurations
• Essential component for exhaust manifold and riser assembly integrity

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Thread Size

.375–16

Length

10.500 inches

Application

Exhaust riser mounting

Drive Type

Alpha, Bravo sterndrive; select inboard

What's in the Box

• 1 × Exhaust Riser Screw

Installation Notes

1. Disconnect the battery and allow the engine to cool completely before starting work.
2. Remove the existing exhaust riser screw, noting its position and orientation.
3. Inspect the threaded hole for corrosion or damage; clean threads if necessary.
4. Insert the new screw and hand-tighten to ensure proper alignment.
5. Torque to manufacturer specifications using a calibrated torque wrench.
6. Verify that all exhaust riser fasteners are equally tightened to maintain a secure seal.
7. Reconnect the battery and perform a visual inspection for proper seating before engine startup.

Troubleshooting & FAQ

How do I confirm this screw fits my MerCruiser engine?

Cross-reference your engine model with the compatibility table above. If your application appears and the OEM part numbers 865982077 or 10-865982077 match your service manual, this screw is correct.

Can I reuse the old screw instead of replacing it?

Reusing corroded or stretched fasteners risks exhaust leaks and riser failure. Always replace exhaust hardware during manifold or riser service to ensure reliable clamping force.

What torque specification should I use?

Refer to your MerCruiser service manual for exact torque values, as specifications vary by engine series. Typical exhaust fasteners require moderate torque with anti-seize compound on threads.

Will this screw work on both carbureted and fuel-injected engines?

Yes, it is compatible with both carbureted and MPI (multi-port injection) MerCruiser engines listed in the compatibility section, regardless of fuel delivery system.

Is anti-seize compound recommended for installation?

Marine-grade anti-seize is highly recommended on exhaust fasteners to prevent corrosion bonding and enable future removal. Apply sparingly to threads before installation.

What are signs that this screw needs replacement?

Visible corrosion, thread damage, stripped heads, or difficulty achieving proper torque indicate replacement is necessary. Exhaust leaks or riser movement also suggest fastener failure.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

• Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and 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 QC.