Yamaha Outboard Drain Plug Screw and Gasket Set – 688-45341-00 / 90340-08002
Yamaha Outboard Drain Plug Screw and Gasket Set – 688-45341-00 / 90340-08002 is backordered and will ship as soon as it is back in stock.
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Yamaha Outboard Drain Plug Screw and Gasket Set – 688-45341-00 / 90...
Yamaha Outboard Drain Plug Screw and Gasket Set – 688-45341-00 / 90340-08002 is backordered and will ship as soon as it is back in stock.
Product Details
This Yamaha outboard drain plug screw and gasket set is intended for lower-unit oil service. The package includes one drain plug, one oil drain screw, and two gaskets. Confirm compatibility by comparing the part numbers and plug arrangement on your engine before ordering.
The listed manufacturer reference numbers are 688-45341-00 and 90340-08002. The supplied gaskets are identified as 90430-08020, quantity two.
- Lower-unit drain plug and oil drain screw service set
- Includes two replacement gaskets
- Suitable for routine gear-oil service when the listed part numbers match
- Aftermarket replacement; not a Yamaha-branded OEM package
Part Number Matrix
Use the following references to compare the required components with the parts being replaced.
| Reference | Component | Package Quantity |
|---|---|---|
| 688-45341-00 | Drain plug | 1 |
| 90340-08002 | Oil drain screw | 1 |
| 90430-08020 | Gasket | 2 |
Engine and Model Compatibility
Fitment is determined by the listed part numbers and the configuration of the lower unit, not by horsepower alone. Yamaha outboard model, year, serial-number, shaft-length, and stroke-specific fitment was not provided for this product. Match your existing components and consult the applicable service information before installation.
| Brand | Application | Reference Numbers | Fitment Guidance |
|---|---|---|---|
| Yamaha Outboard | Lower-unit drain plug and oil drain screw service | 688-45341-00, 90340-08002, 90430-08020 | Verify all numbers and the plug arrangement before purchase |
Technical Specifications
- Application
- Lower-unit drain plug and oil drain screw service
- Product Type
- Drain plug screw and gasket set
- Drain Plug Reference
- 688-45341-00
- Oil Drain Screw Reference
- 90340-08002
- Gasket Reference
- 90430-08020
- Gasket Quantity
- 2
- Brand Status
- Aftermarket replacement; not Yamaha OEM
What's in the Box
- 1× drain plug, reference 688-45341-00
- 1× oil drain screw, reference 90340-08002
- 2× gaskets, reference 90430-08020
Installation Notes
- Place the outboard in a stable vertical position and allow the lower unit to cool before servicing.
- Position a suitable drain pan beneath the lower unit.
- Remove the existing drain plug and oil drain screw with the correct tool.
- Allow the used gear oil to drain fully and inspect the removed hardware.
- Clean the sealing surfaces and inspect the threads in the lower-unit housing for damage or debris.
- Install the new gaskets in the locations specified by the service information for your outboard.
- Thread the replacement plug and screw by hand first to prevent cross-threading, then tighten to the manufacturer’s specified torque.
- Refill the lower unit with the correct gear oil, grade, and quantity specified for your engine.
- Check both sealing points for leaks after servicing and before returning the boat to normal use.
Troubleshooting and FAQ
How do I confirm that this set fits my Yamaha outboard?
Compare your existing drain plug and oil drain screw with references 688-45341-00 and 90340-08002, and confirm the gasket reference 90430-08020. Do not rely only on horsepower or general Yamaha compatibility.
How many gaskets are included?
The set includes two gaskets identified as 90430-08020. Install them according to the service information for your specific lower-unit configuration.
Can I reuse the old gaskets?
Replacement gaskets are recommended during lower-unit oil service. Reusing compressed, damaged, or deformed gaskets can cause seepage.
What torque setting should I use?
Use the torque specification in the service information for your exact Yamaha outboard. Over-tightening can damage threads or the lower-unit housing, while insufficient tightening can cause leaks.
Is this an OEM Yamaha part?
No. This is an aftermarket replacement set supplied with the listed reference numbers and component quantities.
What should I do if the threads or sealing surfaces are damaged?
Do not install the replacement hardware until the damage has been evaluated and repaired. Seek qualified marine-service assistance when necessary.
Safety and Important Information
- Verify the reference numbers, dimensions, plug arrangement, and sealing surfaces against your original components before ordering.
- Horsepower, model year, serial range, shaft length, and stroke are not sufficient by themselves to confirm fitment.
- Use the correct marine gear oil and follow the service procedure for your exact engine.
- Professional installation is recommended if you are unfamiliar with lower-unit service.
About Sea Sierra
- We supply aftermarket marine replacement parts for routine maintenance and repair.
- Parts should be selected by verified reference number and application rather than by general appearance alone.
- For best results, follow the applicable manufacturer service information during installation.
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