Sierra 18-3043 3043 Johnson/Evinrude Impeller

SKU: 4001908 - UPC: 030999315052 - MPN: 18-3043
$37.99 $47.99 ( / )

Available Stock : 21

Keeping your Johnson or Evinrude outboard motor running cool under pressure starts with a reliable water pump impeller. The Sierra 18-3043 impeller steps in as a trusted replacement, engineered to restore optimal cooling performance when wear and tear sets in. Boat owners know the frustration of overheating issues on the...
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Sierra 18-3043 3043 Johnson/Evinrude Impeller Product Description

Keeping your Johnson or Evinrude outboard motor running cool under pressure starts with a reliable water pump impeller. The Sierra 18-3043 impeller steps in as a trusted replacement, engineered to restore optimal cooling performance when wear and tear sets in. Boat owners know the frustration of overheating issues on the water— this impeller tackles that head-on by delivering consistent water flow to protect your engine from costly damage.

Unlike stock parts that might fail prematurely, this Sierra component uses durable neoprene rubber that resists the harsh marine environment, including exposure to ethanol-blended fuels and prolonged dry runs. It's a smart upgrade for anyone maintaining older V4 or V6 models, ensuring your boat stays ready for the next adventure.

Standout Features of the Sierra 18-3043 Impeller

  • Precision-Molded Design: Matches original equipment specifications for a seamless fit inside the water pump housing, minimizing vibration and maximizing pump efficiency.
  • High-Quality Neoprene Construction: Flexible yet tough material that flexes to grab water effectively, even as it ages, outperforming cheaper alternatives that harden and crack quickly.
  • Corrosion-Resistant: Handles saltwater and freshwater exposures without degrading, extending service life in demanding conditions.
  • Easy Identification: Clearly marked for quick verification during routine inspections or service.

These features make it a go-to choice for DIY mechanics and professional marine technicians alike, blending reliability with straightforward replacement.

Perfect Fit for Johnson and Evinrude Outboards

Designed specifically for a wide range of Johnson and Evinrude engines, this impeller fits V4 and V6 configurations from various model years. Always cross-reference with your engine's service manual or parts catalog to confirm compatibility, as pump housings can vary slightly across generations.

Key Benefits for Your Boat's Performance

  • Prevents Overheating: Ensures steady coolant circulation, avoiding warped heads or seized pistons—common failures from neglected impellers.
  • Boosts Longevity: Regular swaps with this part can add seasons of trouble-free operation to your lower unit.
  • Cost-Effective Maintenance: Far less expensive than OEM while matching or exceeding performance, saving you time and money on repairs.
  • Improved Fuel Efficiency: Proper cooling means optimal engine temps, leading to better throttle response and economy.

Pro Tips for Impeller Replacement

Swapping out a worn impeller is a straightforward job that takes under an hour with basic tools. Here's a step-by-step approach to get it right:

  1. Prep the Engine: Tilt the outboard up, remove the lower unit, and drain any water from the pump.
  2. Disassemble the Pump: Twist off the end cap, extract the old impeller using needle-nose pliers or a dedicated puller tool—avoid cutting it out unless necessary to preserve the housing.
  3. Clean Thoroughly: Flush debris and inspect the pump housing and keyway for wear; replace if scored.
  4. Install the New Sierra Impeller: Lubricate with marine grease, align the vanes outward, and use a insertion tool to seat it fully without twisting.
  5. Reassemble and Test: Prime the pump by filling with water or a muffs setup before firing up the engine.

Pro Tip: Replace the impeller every two years or 200-300 hours of use, especially if your boat sits unused. Check for chunks in the tell-tale stream as an early warning sign.

Long-Term Maintenance for Peak Performance

To maximize the life of your Sierra 18-3043 impeller, adopt these habits:

  • Winterize properly by running fresh water through the system and fogging the engine.
  • Avoid dry-running the pump during trailering or storage—use ear muffs for flushing.
  • Monitor for rubber swelling from ethanol fuels; switch to ethanol-free gas if possible.
  • Pair with a fresh water pump gasket and wear plate during replacement for complete refresh.

Boat enthusiasts rave about how this simple maintenance ritual prevents breakdowns and keeps weekends on the water uninterrupted.

Frequently Asked Questions

What engines is the Sierra 18-3043 impeller compatible with?

It fits many Johnson and Evinrude V4 and V6 outboards. Consult your service manual or parts catalog for exact model and year matches.

How often should I replace my outboard impeller?

Every 2-3 years or 200-300 hours of operation, or sooner if you notice reduced water flow from the tell-tale.

Can I install the Sierra 18-3043 impeller myself?

Yes, it's a DIY-friendly task with basic tools. Follow a step-by-step guide, use proper lubrication, and test afterward.

Is the Sierra impeller as good as OEM?

Sierra parts meet or exceed OEM standards using high-grade neoprene, offering reliable performance at a better value.

What causes impellers to fail prematurely?

Common culprits include dry running, age hardening, ethanol fuel damage, and debris buildup in the pump.

Does this impeller work in saltwater environments?

Absolutely—its corrosion-resistant material handles both salt and fresh water without issue.

Should I replace other parts when changing the impeller?

Yes, inspect and often replace the pump housing gasket, wear plate, and key for a complete, leak-free rebuild.

See Sierra Catalog for current application information.



Save $10 when you buy the Sierra 18-3043 3043 Johnson/Evinrude Impeller for only $37 from NVN Marine! Same day shipping before 3pm.

Sierra 18-3043 3043 Johnson/Evinrude Impeller Technical Specifications

Type: 

Engine | Parts / Drive

Vendor: 

Sierra Engine Parts

Weight: 

0.18 lb

Replaces: 

389642

Sierra 18-3043 3043 Johnson/Evinrude Impeller User Reviews

Sierra 18-3043 3043 Johnson/Evinrude Impeller Shipping & Return

Shipping Weight: 

0.18 lb

Box Sizes: 

1.00 (h) x 6.00 (w) x 7.00 (l)

Cubic Feet: 

42.0

Returnable: 

Yes

For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.

Sierra 18-3043 3043 Johnson/Evinrude Impeller

$37.99 $47.99 ( / )