My Account
Shopping Cart

Sierra 18-7840 Fuel Pump Diaphragm for Yamaha Outboard Motors

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-7840
06/02/2036 12:57 AM
Sale Price

$8.30

3 left at this price

delivery box

Usually delivered within 2 days

Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-7840 is a replacement fuel pump diaphragm designed specifically for Yamaha outboard motors. This critical component ensures proper fuel delivery by creating the pressure differential needed to move fuel from the tank to the engine's carburetor or fuel injection system.

Key Features:

  • Precision-engineered for reliable fuel pump operation
  • Manufactured to meet or exceed OEM specifications
  • Designed for direct replacement on compatible Yamaha outboards
  • Durable construction resists fuel degradation and ethanol exposure
  • Essential maintenance part for preventing fuel delivery issues

Regular inspection and replacement of fuel pump diaphragms is critical for maintaining optimal engine performance. A worn or damaged diaphragm can cause hard starting, poor acceleration, fuel starvation at high RPMs, or complete engine failure. Sierra Marine parts are trusted by marine technicians and boat owners worldwide for their quality and reliability.

I recently ordered an Invidia N1 exhaust system from autoplicity and to be honest I was concerned at first my order was not shipped for 2 days, I know I was just very impatient. I'm not sure how their business works but 2 days of processing? I emailed their shipping department and got an email back explaining everything and it also said I would get an email today or the next day and sure enough I did! Had the lowest price for the part I was looking for. Also all the good reviews just made me want to order from this company plus the good prices you can't go wrong.

Definitely the best price that I found for the part that I needed! Customer service was helpful and I got the piece FAST! Thank you so much!

Best price I was able to find anywhere! Very fast shipping and an overall great experience. Will definitely do business with again.

Good availability and good price.

Found pics of louvers on a charger, thought it was pretty cool so I looked for some, found some, this site had lowest price so I bought me some.

I have to return two of my items, still waiting for return information.

Awesome

Your company is always easy to order from, fast to ship and follow up. You're the best out there on the WWW. We appreciate business like you.

very easy to find part

This part has been discontinued years ago, nice to find one.

Excellent service. Fast delivery.

very good

They had the best price on the internet! Fast shipping and repsonse.

Share icon
Return Policy
Returns are easy at Boatplicity

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy