4" Exhaust Thru-Hull, Black w/Flapper
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4" Exhaust Thru-Hull, Black w/Flapper (383-1200325) is a polymer marine wet-exhaust thru-hull fitting designed to route exhaust through the hull while using an integral flapper to help reduce water backflow when the engine is not running.
Key Features
- 4" thru-hull exhaust fitting in black finish
- Includes flapper valve for added backflow protection
- Transom-mounted, wet-exhaust thru-hull style fitting
- Polymer construction helps prevent corrosion and eliminates painting/changing colors from saltwater exposure
Product Compatibility
- Marine wet exhaust systems
- Outboard/inboard exhaust discharge through hull (transom-mounted applications)
- Exhaust hose-to-thru-hull connection setups
Product Details
- Product title: 4" Exhaust Thru-Hull, Black w/Flapper
- SKU: 383-1200325
- Manufacturer part reference: 1200325
- Color: Black
- Nominal size: 4.00" (102mm)
- Ext. length: 3.25" (83mm)
- Length: 7.75" (197mm)
- Diameter: 6.00" (152mm)
- Thru-hull length: 4.50" (114mm)
- Fitting type: thru-hull exhaust fitting with flapper
Parts Desk Insights
Best Use Case: Use this thru-hull fitting when you need a corrosion-resistant, polymer exhaust discharge point for a 4" wet-exhaust hose run and want flapper-type backflow protection at the hull outlet.
Common Issues: If exhaust flow seems restricted or the flapper doesn’t seal properly, confirm the fitting orientation on the transom, inspect the hose connection and mating surfaces, and check for damage or debris around the flapper area (including any needed flapper replacement/service parts).
Related Products & Accessories
- Exhaust Hose Marine Wet Exhaust (4 inch) - Browse the “Exhaust Systems” collection for matching 4" wet-exhaust hose and hose-clamp hardware.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.