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Powerhead Gasket Kit – Fits Yamaha 40HP Enduro 2-Stroke Outboards (Replaces 66T-W0001-01-00)

Sale price $70.00 Regular price $112.00

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Orders are typically processed within 1–2 business days.


U.S. orders usually arrive within 6–15 days, depending on stock location and destination.


International delivery times may vary due to customs processing.


Tracking information will be provided once your order ships.

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 Powerhead Gasket Kit – Fits Yamaha 40HP Enduro 2-Stroke Outboards (Replaces 66T-W0001-01-00) provides all the necessary components for a complete powerhead/cylinder block overhaul. It is designed specifically for Yamaha 40HP 2-Stroke Enduro series outboard engines manufactured from 1998–2012.

This kit serves as a direct replacement for Yamaha 66T-W0001-01-00, Pro Marine 66T-W0001-01-00, and ITACO 66T-W0001-01-02-0.

  • Designed for engine rebuild and overhaul installations.
  • Fits Yamaha's 2-cylinder engine configuration for the 40HP Enduro series.
  • Includes all essential seals and gaskets for a powerhead rebuild.

Part Number Matrix

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

Brand Part Number
Yamaha 66T-W0001-01-00
Pro Marine 66T-W0001-01-00
ITACO 66T-W0001-01-02-0

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This kit is verified for compatibility with the following Yamaha Enduro models.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Yamaha 40X Enduro 40 2-Stroke 1998–2012 66T-W0001-01-00 Manual starter, tiller handle models
Yamaha E40X Enduro 40 2-Stroke 1998–2012 66T-W0001-01-00
Yamaha 40XMH 40 2-Stroke 1998–2012 66T-W0001-01-00
Yamaha E40XMH 40 2-Stroke 1998–2012 66T-W0001-01-00
Yamaha 40XW 40 2-Stroke 1998–2012 66T-W0001-01-00
Yamaha 40XWT 40 2-Stroke 1998–2012 66T-W0001-01-00

Technical Specs

Product Type
Powerhead Gasket Kit
Installation
Engine rebuild/overhaul
Fuel Type
Gasoline (pre-mix oil)
Housing Material
Paper, Rubber, Metal (varies by gasket)
Product Dimensions
30.5 cm L x 21.0 cm W x 2.5 cm H
Operating Temperature
-20°C to 120°C (estimated)
Warranty
Manufacturer standard warranty
Technical Attributes
Fits Yamaha 2-cylinder engine configuration

What’s in the Box

Complete gasket and seal kit for Yamaha 40HP Enduro 2-stroke engine, including:

  • Cylinder head gaskets
  • Base gaskets
  • Intake and exhaust gaskets
  • Crankcase seals
  • O-rings
  • Other necessary sealing components for powerhead rebuild

Installation Notes

  1. Disconnect the battery and all fuel lines to ensure safety. Drain remaining fluids like gasoline and oil from the engine.
  2. Carefully remove the powerhead assembly from the outboard's midsection according to your service manual.
  3. Disassemble the powerhead on a clean workbench, keeping all parts organized. Pay close attention to the order and orientation of components.
  4. Thoroughly clean all mating surfaces to remove old gasket material and residue. Avoid scratching or gouging the metal surfaces.
  5. Install the new gaskets and seals from the kit. Ensure each component is correctly seated in its designated location.
  6. Reassemble the powerhead. Tighten all bolts to the manufacturer's specified torque values and follow the correct tightening sequence.
  7. Reinstall the fully assembled powerhead onto the midsection.
  8. Reconnect the fuel lines, battery cables, and any other control linkages. Refill with fresh fuel/oil mix and perform a thorough leak check before starting the engine.

Troubleshooting & FAQ

Will this kit fit my specific Yamaha 40HP Enduro model?

This kit is designed for the Yamaha 40HP 2-Stroke Enduro outboard engine series made from 1998–2012, including models 40X, E40X, 40XMH, E40XMH, 40XW, and 40XWT. Always verify your model and year before purchasing.

Does this kit include every gasket needed for a complete powerhead rebuild?

Yes, this is a complete powerhead gasket kit containing the essential gaskets, seals, and O-rings for a standard rebuild of the cylinder block, including cylinder head, base, intake, exhaust, and crankcase components.

How can I tell if my powerhead gaskets need replacement?

Common symptoms of a failed powerhead gasket include loss of engine compression, water detected in the cylinders, visible water or oil leaks on the engine block, and persistent engine overheating that is not resolved by cooling system service.

Should I use sealant with these gaskets?

It is critical to consult your engine's official service manual. Some gaskets are designed to be installed dry, while others may require a specific type of sealant. Using sealant where it is not specified can cause issues.

Is this kit compatible with Parsun engines?

While some aftermarket cross-references suggest compatibility with certain Parsun 40HP 2-stroke models, we lack the specific model and year data to confirm fitment. Purchase for a Parsun engine only if you can visually match the gaskets to your old ones.

What's the difference between OEM and aftermarket parts?

This listing is an aftermarket replacement, not an original equipment manufacturer (OEM) part. It is engineered to meet or exceed OEM-level specifications using comparable materials and is manufactured in an ISO 9002 certified facility with batch inspections for quality control.

What are the shipping speeds and costs?

We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most locations, with expedited options available at checkout where applicable.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition.

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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