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We will be closing at 12 PM EST on Friday, April 18th, in observance of Good Friday and Easter.
Any orders placed after this time will be processed on Monday, April 21st.
Have a happy Easter weekend!

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Due to severe weather, our White House, Tennesee location will be closed Wednesday the 19th.

All shipments from this location will resume on Thursday the 20th. Thank you for your patience!

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Inboard & I/O Engine Parts

Inboard Marine Engine Parts and Accessories

As the largest online dealer of inboard boat parts, Marine Parts Source will help you find the right engine parts you need for any project. We’re here to assist with seasonal maintenance, major repairs and more so you can get back on the water. Use our convenient categories to browse our collection — or if you know the part number you need, enter it into the search bar. From oil and fuel filters to spark plugs, exhaust manifolds, bell housings, starters and alternator belts, we supply boat owners from coast to coast.

You can always count on quality and knowledge when you shop with us. We’re an authorized dealer of the leading OEM and aftermarket performance inboard marine brands, including J&N Electric, Sierra, Arco Marine, Volvo Penta and Crusader. If you have a question, our sales associates have the technical expertise to answer it. Enjoy free ground shipping on qualifying orders so your vessel is ready for adventure.

Inboard & I/O Engine Parts

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  1. Sierra 18-9440CAT-4 25W-40 Synthetic Blend Catalyst Engine Oil - 5 qt.
    25W-40 Synthetic Blend Catalyst Engine Oil, 5 quart | Sierra 18-9440CAT-4
    SIERRA-18-9440CAT-4
    Qty In Stock: 137
    Brand: Sierra

    Synthetic blend 25W-40 engine oil is formulated for all 4-stroke applications including outboard, sterndrive, and inboard marine engines with catalyst emission systems. NMMA FC-W/API-SL certified and approved.

    Learn More
    MSRP: $74.39 $46.29
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  2. Small Image
    SAE 30 Full Synthetic Marine Engine Oil, 1 quart | Sierra 18-9410-2
    SIERRA-18-9410-2
    Qty In Stock: 38
    Brand: Sierra

    Fully synthetic straight 30 weight engine oil is formulated for inboard & stern drive marine engines

    Learn More
    MSRP: $16.39 $11.55
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  3. 1 Quart 4 Stroke Full Synthetic Oil 10W-30 | Sierra 18-9690-2
    1 Quart 4 Stroke Full Synthetic Oil 10W-30 | Sierra 18-9690-2
    SIERRA-18-9690-2
    Qty In Stock: 1
    Brand: Sierra

    Sierra's full synthetic engine oil optimizes engine life by reducing friction while providing wear protection in severe operating conditions. Used with outboard and sterndrive applications.

    Learn More
    MSRP: $20.79 $15.17
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  4. Sierra 18-9554-2 1 Quart 15W-40 Multi Vehicle Oil
    1 Quart 15W-40 Multi Vehicle Oil | Sierra 18-9554-2
    SIERRA-18-9554-2
    Qty In Stock: 19
    Oil 15W-40 Multi Vehicle Learn More
    MSRP: $10.59 $8.77
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    25W-40 Catalyst Marine Engine Oil, 5 quart | Sierra 18-9400CAT-4
    SIERRA-18-9400CAT-4
    Qty In Stock: 165
    Brand: Sierra
    Sierra's Premium Blend 25W-40 catalyst engine oil is specially formulated to meet the needs of 4-stroke marine engines with catalyst emission systems. Learn More
    MSRP: $57.69 $38.66
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