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Attention! We will be short staffed from Sept 29 through Oct 10th. Phone support will be limited, but orders will still ship as normal. The best way to send support requests is through the contact bubble at the bottom right of the website. 

Exhaust Flappers

Exhaust Flappers

  • Sierra EXHAUST FLAPPER 5-6 INCH 18-4458

    Sierra

    Sierra EXHAUST FLAPPER 5-6 INCH 18-4458

    $70.69 $51.90
    Sierra_47 - 18-4458 EXHAUST FLAPPER 5-6 INCH EXHAUST PROTECTOR VALVE (Sierra) Includes: • Stainless steel hose clamp • Weather resistant rubber flapper valve Replaces OEM No: Volvo# 834438-4 Size 5" & 6" Alternate - SIE...
    $70.69 $51.90
  • On Sale
    SEACHOICE EXHAUST GARD COVER-4  (2/CARD 28361

    SEACHOICE

    SEACHOICE EXHAUST GARD COVER-4 (2/CARD 28361

    $30.59 $29.48
    Seachoice - 28361 EXHAUST GARD COVER-4 (2/CARD EXHAUST GUARD COVER) Black rubber with adjustable stainless steel clamp. Flap valve prevents following seas from entering exhaust outlet when stopping or moving slowly. All stainless steel clamps included. ...
    $30.59 $29.48
  • Sierra EXHAUST FLAPPER 4 INCH 18-4457

    Sierra

    Sierra EXHAUST FLAPPER 4 INCH 18-4457

    $36.59 $30.20
    Sierra_47 - 18-4457 EXHAUST FLAPPER 4 INCH EXHAUST PROTECTOR VALVE (Sierra) Includes: • Stainless steel hose clamp.  • Weather resistant rubber flapper valve Replaces: MerCruiser 12644A Size 4" Alternate - SIE 4457 18-4457...
    $36.59 $30.20
  • MerCruiser EXHAUST FLAPPER (QUICKSILVER) 12644A1

    Mercury Marine / Quicksilver

    MerCruiser EXHAUST FLAPPER (QUICKSILVER) 12644A1

    $43.17 $36.44
    MerCruiser EXHAUST FLAPPER (QUICKSILVER) 12644A1 Flapper and clamp included Please confirm fitment of MerCruiser parts with your serial numberPhotos and descriptions provided via Mercury may not always be accurateAll of our Mercury parts are sold and...
    $43.17 $36.44
  • On Sale
    Sierra EXHAUST FLAPPER 3 INCH 18-4456

    Sierra

    Sierra EXHAUST FLAPPER 3 INCH 18-4456

    $36.59 $28.83
    Sierra_47 - 18-4456 EXHAUST FLAPPER 3 INCH EXHAUST PROTECTOR VALVE (Sierra) Includes: • Stainless steel hose clamp • Weather resistant rubber flapper valve Replaces: MerCruiser 34565A1, A2 Size 3" Alternate - SIE 4456...
    $36.59 $28.83

 MerCruiser Exhaust Flappers

If you need to replace your MerCruiser exhaust flapper, NuWave Marine has got you covered with OEM parts, as well as aftermarket parts from trusted companies like Sierra and SEACHOICE.

A big part of keeping your boat’s engine running optimally is preventing water from sneaking into it. Exhaust flappers attach to the exhaust of a boat, and are designed to open when exhaust gasses are being vented, and close when they are not. Your MerCruiser exhaust system will need to be monitored at regular intervals to check for wear, and it’s always a good idea to take a look at your exhaust flappers, too. They can be damaged by prolonged exposure to hot exhaust, or just from extended use.

MerCruiser Exhaust Flapper

Whether your boat has a new MerCruiser 2100+ EC exhaust or an older design, you’ll need replacement flappers that are designed to fit. From small 3” flappers to larger 5-6” sizes, the experts at NuWave Marine can help you figure out which design works for your exhaust system. Of course, replacing the whole exhaust system might be the best choice, especially if it’s been several seasons since it was last serviced. Check out NuWave Marine’s MerCruiser OEM exhaust kits and find the set that’s right for you.

MerCruiser 5.7 Exhaust Flapper Replacement

In addition to 5.7 replacement flappers, we also carry the MerCruiser 3.0 exhaust flapper and the MerCruiser 4.3 exhaust flapper. With the right fit, you can be sure that water won’t be able to backflow into your engine. You’ll keep your boat on the water and your motor performing like it should.

Put Your Trust in High-Quality Parts

NuWave Marine has been servicing MerCruiser exhausts for decades, and we know that investing in quality parts is the best way to avoid a system failure that could be catastrophic for your boat’s engine. From simple replacement parts like gaskets and bolts, to manifolds, risers, and MerCruiser thru transom fittings, we only stock parts that are dependable and reliable.