Sierra 18-5642
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Within 30 days
Sierra 18-5642 Product Description
Revitalize your Mercury or Mariner outboard with the reliable Sierra 18-5642 starter, a precision-engineered replacement that matches the performance of the original Mercury-Mariner 50-893891T unit. Designed for boaters who demand durability on the water, this starter tackles the harsh marine environment, from saltwater corrosion to constant vibration, ensuring your engine fires up every time you hit the throttle.
Whether you're prepping for a weekend fishing trip or maintaining your vessel for commercial use, this starter delivers consistent cranking power without the hassle of OEM pricing. Boaters trust Sierra for its commitment to quality aftermarket parts that extend engine life and minimize downtime.
Key Features and Performance Advantages
- Corrosion-Resistant Construction: Built with marine-grade materials to withstand saltwater exposure, humidity, and UV rays, preventing premature failure common in coastal applications.
- High-Torque Design: Provides superior cranking speed for reliable starts in cold conditions or with heavily loaded batteries, reducing wear on your engine's flywheel.
- Direct OEM Fitment: Engineered as a drop-in replacement, eliminating the need for modifications and ensuring seamless integration with your existing electrical system.
- Solenoid Integration: Includes a robust solenoid for instant engagement, minimizing electrical arcing and extending contact point life.
- Lightweight Yet Sturdy: Optimized weight reduces overall engine stress while maintaining the strength needed for high-horsepower demands.
Unlike generic starters that fail under load, the Sierra 18-5642 undergoes rigorous testing for amperage draw, pinion engagement, and endurance, giving you peace of mind on long runs or in rough seas.
Perfect Fit for Popular Mercury and Mariner Models
This starter is tailored for a range of 4-stroke Mercury and Mariner outboards, ensuring broad compatibility across recreational and light commercial boats. Common applications include:
- 25 HP EFI 4-stroke models
- 30 HP EFI 4-stroke outboards
- 40-60 HP 4-stroke engines (select configurations)
- Various Mercury-Mariner tiller and remote steer setups
Always cross-reference your engine's serial number for exact fitment to avoid mismatches. This part shines in setups where quick starts are critical, like tournament bass boats or charter operations.
Easy Installation and Pro Tips
Swapping out a faulty starter is a straightforward DIY job for most boaters, typically taking under an hour with basic tools. Here's a step-by-step guide:
- Disconnect the battery to prevent shorts—safety first.
- Remove the cowling and locate the starter, usually bolted near the flywheel.
- Unbolt the mounting brackets (two or three bolts) and disconnect wiring harnesses, noting positive/negative leads.
- Install the new Sierra unit, torque bolts to spec (around 15-20 ft-lbs), and reconnect wires securely.
- Test crank the engine before full reassembly.
Pro Tip: Inspect your battery terminals and grounds during replacement. Corrosion here often mimics starter failure. Clean with a baking soda solution and apply dielectric grease for longevity.
"Replaced my old starter on a '15 Mercury 25hp—fired right up smoother than new. Worth every minute." – Experienced boater feedback.
Maximize Longevity with Simple Maintenance
To get years of service from your Sierra starter:
- Keep battery charged above 12.6V to avoid excessive cranking strain.
- Flush the engine after saltwater use to minimize solenoid buildup.
- Check wiring for frays annually—vibration is a silent killer.
- Avoid rapid-fire starting attempts; give it 10-15 seconds between tries.
Spotting issues early? Listen for clicking (solenoid fault), grinding (worn gears), or slow cranking (low amps). Addressing these promptly prevents cascading failures in your ignition system.
Frequently Asked Questions
What are the signs my Mercury outboard starter needs replacement?
Common symptoms include a single click when turning the key, slow or no cranking, grinding noises during start attempts, or visible corrosion on terminals. If the solenoid engages but the pinion doesn't mesh, it's often time for a new unit like the Sierra 18-5642.
Is the Sierra 18-5642 compatible with all Mercury 4-strokes?
It's designed for specific 25-60 HP 4-stroke EFI models. Check your OEM part number 50-893891T match and engine serial for confirmation. It's a popular fit for many tiller-handle setups.
How does Sierra quality compare to genuine Mercury parts?
Sierra uses OEM-spec materials and rigorous testing, often at a fraction of the cost. Many boaters report equal or better longevity due to enhanced corrosion resistance tailored for marine use.
Can I install this starter myself without special tools?
Yes, basic socket set, wrenches, and a torque wrench suffice. No engine hoist needed. Just ensure the battery is disconnected and follow torque specs for bolts.
Will this starter work with my battery upgrades?
Absolutely—it's compatible with standard marine batteries or AGM upgrades. Ensure proper cable gauge to handle the amperage draw for optimal performance.
What warranty does the Sierra 18-5642 come with?
Sierra offers a manufacturer-backed warranty focused on defects in materials and workmanship. Details vary by retailer, but it's built to last seasons of heavy use.
Does it fit Mariner engines as well?
Yes, as a Mercury-Mariner cross-compatible part, it works seamlessly with equivalent Mariner models sharing the 50-893891T OEM number.
Save $59 when you buy the Sierra 18-5642 for only $235 from NVN Marine! Same day shipping before 3pm.
Sierra 18-5642 Technical Specifications
| Type: | |
|---|---|
| Vendor: |
Sierra Engine Parts |
| Weight: |
7.63 lb |
Sierra 18-5642 User Reviews
Sierra 18-5642 Shipping & Return
| Shipping Weight: |
7.63 lb |
|---|---|
| Box Sizes: |
4.00 (h) x 4.00 (w) x 13.00 (l) |
| Cubic Feet: |
208.0 |
| Returnable: |
Yes |
For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.