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Gasket Under Oil Seal – Fits Suzuki DT40 Outboard Engines (Replaces 11433-94412, 11433-94411)

Sale price $16.90 Regular price $27.00
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Gasket Under Oil Seal – Fits Suzuki DT40 Outboard Engines (Replaces 11433-94412, 11433-94411) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 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.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This aftermarket Gasket Under Oil Seal – Fits Suzuki DT40 Outboard Engines provides a reliable seal between the powerhead and engine base plate. It is designed for Suzuki 2-Stroke 35–40 HP models, including the DT40 and DT35TCLK series manufactured between 1986 and 2000.

It serves as a direct replacement for Suzuki OEM part numbers 11433-94411, 11433-94412, 11433-94412-000, 11433-92L00, and 11433-94410.

  • Installs between the powerhead/engine block and engine base plate.
  • Made from a durable, high-quality aftermarket paper/composite material.
  • Engineered to seal the powerhead assembly in a marine environment.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number Notes
Suzuki 11433-94411 Interchangeable part number
Suzuki 11433-94412 Interchangeable part number
Suzuki 11433-94412-000 Superseded or alternative number
Suzuki 11433-92L00 Superseded or alternative number
Suzuki 11433-94410 Superseded or alternative number

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This gasket is designed specifically for the listed Suzuki 2-stroke outboard models.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Suzuki DT40C 40 2-Stroke 1986–2000 11433-94412/11433-94411 Under oil seal gasket
Suzuki DT40W 40 2-Stroke 1986–2000 11433-94412/11433-94411 Under oil seal gasket
Suzuki DT40G 40 2-Stroke 1986–2000 11433-94412/11433-94411 Under oil seal gasket
Suzuki DT40X 40 2-Stroke 1986–2000 11433-94412/11433-94411 Under oil seal gasket
Suzuki DT35TCLK 35 2-Stroke 1986–2000 11433-94412/11433-94411 Under oil seal gasket

Technical Specs

Product Type
Under Oil Seal Gasket
Installation
Between powerhead/engine block and engine base plate
Fuel Type
Gasoline
Engine Type
2-Stroke Outboard
Engine Position
Outboard
Material
Aftermarket replacement material (paper/composite)
Dimensions
22.3 cm L x 22.0 cm W x 0.3 cm H
Condition
New
Warranty
Varies by manufacturer (typically 90 days to 1 year)
Other Technical Attributes
Part of the powerhead sealing system

What’s in the Box

  • 1 x Gasket Under Oil Seal (Replaces 11433-94412/11433-94411)

Installation Notes

  1. Disconnect the battery and all fuel lines for safety.
  2. Carefully remove the powerhead from the engine's base plate, following the manufacturer's service manual.
  3. Remove the old gasket completely. Thoroughly clean and degrease both mating surfaces to ensure they are free of old material and debris.
  4. Place the new gasket into position, ensuring it aligns perfectly with all bolt holes and passages.
  5. Reinstall the powerhead. Tighten all bolts in the correct sequence and to the manufacturer-specified torque values to ensure an even seal.
  6. Reconnect the fuel lines and battery. Before operating on the water, check for any fuel or exhaust leaks.

Troubleshooting & FAQ

How do I confirm this gasket fits my Suzuki DT40?

This part is specifically for Suzuki DT40 and DT35 models made from 1986–2000. Verify your model and year using the compatibility table. The most reliable method is to match your old part's number to one of the cross-referenced numbers: 11433-94412, 11433-94411, 11433-92L00, or 11433-94410.

What are the signs of a failing under oil seal gasket?

Common symptoms include oil or fuel leaks visible between the powerhead and the lower unit, a drop in engine performance, unusual exhaust smoke, or water contamination in the oil. A visual inspection for cracks or degradation of the existing gasket is also a clear indicator.

Are part numbers 11433-94412 and 11433-94411 interchangeable?

Yes, all available data indicates that these part numbers are interchangeable. One likely superseded the other over time, but both refer to the same gasket for the specified engine models. This listing replaces both.

How often should this gasket be replaced?

This gasket does not have a fixed replacement interval. It should be replaced anytime the powerhead is removed for service, if it shows signs of leaking, or if it has become brittle and compressed due to age and heat cycles.

What is the difference between this and an original Suzuki gasket?

This is an aftermarket part designed to meet or exceed OEM specifications for fit, form, and function. It is made from comparable high-quality composite materials to ensure a durable seal in marine conditions but is available at a more competitive price point.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

  • Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement, not an OEM component.
  • Professional installation is recommended for safety and performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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