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Power Head Gasket Kit – Fits Suzuki DF40/DF50 4-Stroke Outboards (Replaces 11400-87804)

Regular price $128.61
Shipping calculated at checkout.

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 Power Head Gasket Kit is engineered for Suzuki DF40 and DF50 4-stroke outboard engines manufactured between 1999 and 2010. The set includes all necessary gaskets for a complete engine overhaul, ensuring a precise fit and reliable seal to restore performance.

It serves as a direct replacement for Suzuki part numbers 11400-87800 through 11400-87805, and Johnson/Evinrude equivalents 5031302, 5034354, and 5036714.

  • Designed for engine overhaul replacement.
  • Includes a complete set of power head gaskets.
  • Note: Oil seals are not included in this kit.

Part Number Matrix

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

Brand Part Number Superseded By
Suzuki 11400-87800 11400-87801
Suzuki 11400-87801 11400-87802
Suzuki 11400-87802 11400-87803
Suzuki 11400-87803 11400-87804
Suzuki 11400-87804 11400-87805
Johnson/Evinrude 5031302 5034354
Johnson/Evinrude 5034354 5036714

Engine & Model Compatibility

Confirm your engine model/year in the table below.

These models were produced by Suzuki and also branded for Johnson/Evinrude by Bombardier/OMC.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Suzuki DF40 40 4-Stroke 1999–2010 11400-87804 Superseded by 11400-87805
Suzuki DF50 50 4-Stroke 1999–2010 11400-87804 Superseded by 11400-87805
Johnson J40HP 40 4-Stroke 1999–2010 5034354 Bombardier/OMC branded Suzuki engine
Johnson J50HP 50 4-Stroke 1999–2010 5034354 Bombardier/OMC branded Suzuki engine

Technical Specs

Product Type
Power Head Gasket Kit
Installation
Engine Overhaul Replacement
Housing Material
Paper/Rubber Composites
Compatibility
Suzuki DF40, DF50 4-Stroke Outboards
Model Years
1999–2010
Package Dimensions
36.5 cm L × 24.5 cm W × 3.0 cm H

What’s in the Box

  • 1 x Complete Power Head Gasket Set (single assembly)

Installation Notes

  1. Disconnect the battery and all fuel lines for safety.
  2. Drain engine fluids, including oil and coolant, into appropriate containers.
  3. Systematically disassemble the engine's power head, organizing all parts and fasteners.
  4. Remove the old gaskets and thoroughly clean all mating surfaces until they are free of old material and debris.
  5. Position the new gaskets correctly, ensuring proper alignment with all passages and bolt holes.
  6. Reassemble the power head, torquing all bolts to the manufacturer's specifications in the correct sequence.
  7. Reconnect fuel lines, refill with fresh fluids, and attach the battery cables.
  8. Before starting, inspect for any leaks. Run the engine briefly and check again.

Troubleshooting & FAQ

How do I confirm this kit fits my specific engine?

Verify your engine's model and year against the "Engine & Model Compatibility" table. Cross-reference your existing part number with those listed in the "Part Number Matrix" for an exact match.

What are common signs of a failed power head gasket?

Symptoms include engine overheating, loss of compression, water in the engine oil (milky appearance), white smoke from the exhaust, and rough idling. These indicate a breach in the seal between the cylinder head and engine block.

Does this gasket kit include oil seals?

No, this kit contains all gaskets required for a power head overhaul but does not include oil seals. Oil seals should be purchased separately if needed for your repair.

Is sealant necessary with these gaskets?

Generally, these gaskets are designed to be installed dry. However, always consult your engine's service manual, as a thin layer of non-hardening sealant may be recommended on specific areas.

Can I reuse my existing head bolts?

It is strongly recommended to use new head bolts during an overhaul. Old bolts can stretch and may not achieve the correct torque, potentially leading to gasket failure. Always follow the torque-to-yield procedures specified in your service manual.

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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