These Sierra marine fuel/water separator kits pair an aluminum mounting head with a spin-on filter element. They are available in 10- and 21-micron versions, each with short or tall filter options. The filter element, fuel-system requirements and threaded port size all matter when choosing a kit.
Choose by filter element and filtration rating
18-7848-1 is the short 18-7844 filter kit; 18-7852-1 uses the tall 18-7845 element. Sierra's catalog identifies these kits for carbureted-engine applications.
18-7983-1 has the short 18-7944 element, while 18-7982-1 uses the taller 18-7945. Consult the engine manufacturer before changing filtration.
Sierra 10- and 21-micron fuel/water separator kits
The four kit numbers below are manufacturer-catalogued with an aluminum filter head and spin-on element. The table identifies the element number rather than relying on a generic filter description.
| Kit MPN | Micron rating | Filter height | Spin-on element | Head MPN | Head ports |
|---|---|---|---|---|---|
| 18-7848-1 | 21 micron | Short | 18-7844 | 18-7853-1 | ¼-inch pipe threads |
| 18-7852-1 | 21 micron | Tall | 18-7845 | 18-7853-1 | ¼-inch pipe threads |
| 18-7982-1 | 10 micron | Tall | 18-7945 | 18-7853-1 | ¼-inch pipe threads |
| 18-7983-1 | 10 micron | Short | 18-7944 | 18-7853-1 | ¼-inch pipe threads |
Mounting heads and threaded connections
All four reference kits are listed with an 18-7853-1 aluminum mounting head and two ¼-inch pipe plugs. The ¼-inch measurement describes the threaded pipe ports on the head, not the outside diameter of a hose. Choose compatible fuel-line fittings separately where required.
Sierra lists these four numbers as kits, with one spin-on element, one 18-7853-1 mounting head and two 18-4256 pipe plugs. A separately sold filter element is not the same package.
Installation and maintenance considerations
Mount the assembly in the location specified by the boat and engine manufacturers. Verify filter clearance, fuel-line fittings, bracket support and the system's required filtration rating. After service, check for leaks and correct operation using the specified procedure.
The manufacturer's 21-micron kit chart is labelled for carbureted engines. Actual engine requirements may differ; verify the specified filter media and water-separation arrangement before installation.
Sierra marine fuel/water separator kits
Choose the required kit number below to review its product page and availability.
Sierra 18-7848-1
Short 21-micron spin-on filter kit with aluminum head and two pipe plugs.
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Sierra 18-7852-1
Tall 21-micron alternative with a different filter element length.
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Sierra 18-7982-1
Tall 10-micron kit with head and mounting hardware listed in Sierra's catalog.
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Sierra 18-7983-1
Short 10-micron kit with a ¼-inch threaded aluminum head and two pipe plugs.
View product details and availabilityOther marine fuel filtration guides
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