





Sierra International 18-7844 Fuel Filter – 21 Micron Mercury Marine Replacement
- £29.07
- £29.07
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Description
xOverview
Meet the Sierra 18-7844 fuel filter, a compact Mercury Marine replacement engineered for reliable filtration and steady fuel flow. With a 21 micron rating, it targets fine particulates while supporting demanding engines. It replaces Mercury Marine parts 35-807172 and 35-802893Q, offering an OEM-equivalent fit for peace of mind on the water.
Performance and filtration
Ethanol blended fuels can carry more water and particulates. This filter is built to manage that reality without compromising fuel delivery. Designed to feed even higher-demand motors, the 90 GPH flow rating helps keep fuel moving consistently.
- 90 GPH flow supports steady fuel supply for many boats
- 21 micron rating captures small particulates
- Handles ethanol blended fuels that may carry more water
- Thread pitch 42690 ensures secure installation
Compatibility and installation
These specs reflect a short filter form that fits compatible housings. Short length is approximately 3.875 inches, making installation straightforward in compact setups.
- Replaces Mercury Marine part numbers 35-807172 and 35-802893Q
- OEM origin: Mercury Marine 35-807172
- Short length about 3.875 inches
- Thread pitch 42690 for proper fit
Why choose Sierra
Sierra offers OEM-equivalent filtration parts designed for longevity and reliable filtration performance. This model supports clean fuel paths, helping to minimize clog risk and maintain smooth operation under typical boating conditions. Use as part of regular maintenance to keep fuel systems in good shape.
Note: Benefits described reflect the filter's design attributes and compatibility. Real-world results depend on engine condition, fuel quality, and maintenance practices.
FAQ
Q: Is the Sierra 18-7844 a Mercury Marine replacement?
A: Yes, it replaces Mercury Marine parts 35-807172 and 35-802893Q and features a 21 micron rating.
Q: What performance can I expect from this filter?
A: The filter supports up to 90 GPH flow and helps reduce particulates in ethanol blended fuel for smoother operation.
Shipping & Return
xReturns Policy
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Shipping
We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
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