Sierra 18-8402-1

Upgrade Your Outboard with Reliable Sierra Starter Bolt 18-8402-1

When your boat's starter motor starts to wobble or fails under the strain of repeated use on the water, a single loose or worn bolt can turn a quick trip into a major headache. The Sierra 18-8402-1 starter bolt steps in as the dependable fix, engineered as a direct replacement for the Mercury Marine 10-813642. This isn't just any fastener—it's precision-machined to handle the vibrations, corrosion, and torque demands of marine environments, keeping your engine firing smoothly every time.

Crafted from high-grade stainless steel, this bolt resists saltwater exposure and maintains its grip even after seasons of hard running. Boat owners swear by it for restoring factory-tight security to the starter assembly, preventing misalignment that leads to poor cranking or complete starter failure.

Perfect Fit for Mercury Outboards and More

Designed specifically for a wide range of Mercury outboard models, the Sierra 18-8402-1 ensures bolt-on compatibility without the guesswork. It's the go-to choice for mechanics and DIY enthusiasts tackling everything from classic 2-strokes to modern EFI powerplants. Key compatibility highlights include:

• Inline and V6 Mercury engines
• Popular carbureted and fuel-injected setups
• High-performance racing applications where every ounce of reliability counts

Before installing, double-check your engine serial number against Sierra's cross-reference charts—peace of mind starts with the right match.

Why Sierra Engine Parts Outshine the Rest

Sierra has built a reputation in the boating world for aftermarket parts that match or exceed OEM standards at a fraction of the hassle. Unlike generic hardware store bolts that rust out after one season, the 18-8402-1 features:

• Corrosion-resistant coating for extended saltwater life
• Exact thread pitch and length for secure mounting
• Meets or exceeds Mercury's rigorous engineering specs
• Backed by Sierra's commitment to quality control

Opting for Sierra means fewer trips to the marina for fixes and more time enjoying the water. It's a small part that delivers big on reliability.

Simple Installation to Get You Back on the Water Fast

Swapping out your starter bolt is a straightforward job that most boaters can handle in under 30 minutes with basic tools. Here's a quick step-by-step:

1. Safety first: Disconnect the battery and secure the boat on a trailer or calm water.
2. Remove the old bolt using a deep socket or wrench—watch for stripped threads from over-torquing.
3. Clean the mounting hole thoroughly to remove corrosion or debris.
4. Apply marine-grade anti-seize to the new Sierra bolt threads.
5. Torque to Mercury specs (typically 20-25 ft-lbs—consult your manual) and reconnect everything.
6. Test crank the engine to confirm smooth operation.

Pro tip: While you're in there, inspect the starter solenoid and battery cables for wear—they often contribute to starting issues.

Maintenance Tips to Prolong Starter Life

To avoid future bolt woes, incorporate these habits into your routine:

• Rinse the engine with fresh water after every saltwater outing.
• Check bolt torque annually or every 100 hours of use.
• Keep battery terminals clean and connections tight.
• Store your boat with the battery on a trickle charger during off-seasons.

These simple steps can extend the life of your starter assembly by years, saving you time and frustration.