CDI Unit Assembly – Fits Yamaha 9.9HP/15HP 2-Stroke Outboards (Replaces 6B4-85540-00, 6B4-85540-01, 6B4-85540-03)
CDI Unit Assembly – Fits Yamaha 9.9HP/15HP 2-Stroke Outboards (Replaces 6B4-85540-00, 6B4-85540-01, 6B4-85540-03) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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
Delivery and Shipping
Free standard shipping on all orders under 1 KG
CDI Unit Assembly – Fits Yamaha 9.9HP/15HP 2-Stroke Outboards (Repl...
Product Details
This aftermarket CDI Unit Assembly – Fits Yamaha 9.9HP/15HP 2-Stroke Outboards (Replaces 6B4-85540-00, 6B4-85540-01, 6B4-85540-03) provides a reliable ignition signal for consistent engine performance. It is engineered to fit a range of Yamaha 2-Stroke 9.9HP and 15HP outboard engines from 2000–2006, including the E9.9/E15 and T9.9/T15 series, as well as compatible Parsun T15 2-stroke models.
It serves as a direct interchange for Yamaha part numbers 6B4-85540-00, 6B4-85540-01, and 6B4-85540-03, and Parsun T15-05000300 or TE15-05000300.
- Engineered for direct plug-and-play installation.
- Controls ignition timing based on engine RPM for optimal spark.
- Built with a durable metal and rubber compound housing to protect internal electronics.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6B4-85540-00 |
| Yamaha | 6B4-85540-01 |
| Yamaha | 6B4-85540-03 |
| Parsun | T15-05000300 |
| Parsun | TE15-05000300 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | E9.9D/E15D | 9.9/15 | 2-Stroke | 2000–2006 | 6B4-85540-00/01/03 | |
| Yamaha | 9.9HP/15HP | 9.9/15 | 2-Stroke | 2000–2006 | 6B4-85540-00/01/03 | |
| Yamaha | T9.9/T15 | 9.9/15 | 2-Stroke | 2000–2006 | 6B4-85540-00/01/03 | |
| Parsun | T15 | 15 | 2-Stroke | TE15-05000300 | Compatible with Yamaha design |
Technical Specs
- Product Type
- CDI Unit Assembly (Capacitor Discharge Ignition)
- Installation
- Direct replacement, plug-and-play
- Fuel Type
- Gasoline
- Connection
- Multi-pin electrical connector
- Housing Material
- Metal and rubber compound
- Housing Color
- Black
- Dimensions
- 10.5cm x 10.5cm x 6.0cm (L x W x H)
- Fitting Type
- Direct electrical plug-in
- Other Technical Attributes
- High voltage output (30,000-50,000 volts), controls ignition timing based on engine RPM
What’s in the Box
- 1 x CDI Unit Assembly
Installation Notes
- Ensure the engine is off and the battery is disconnected before starting.
- Locate and identify the old CDI unit on the engine.
- Carefully unplug the main electrical connector from the unit.
- Unscrew the mounting bolts holding the old CDI unit in place and remove it.
- Position the new CDI unit and secure it with the original mounting bolts.
- Firmly push the electrical connector into the new unit until it clicks into place.
- Reconnect the battery, start the engine, and verify proper operation.
Troubleshooting & FAQ
How do I know if my CDI unit has failed?
Common signs of CDI failure include difficulty starting, intermittent stalling, engine misfires at certain RPMs, weak or no spark, and a complete failure to start. A spark tester can help diagnose a lack of spark.
Is this compatible with models outside the listed years?
We can only guarantee fitment for the specified Yamaha models and years (2000–2006). Using this part on other models or years is not recommended, as internal timing curves may differ.
What's the difference between this and an original OEM part?
This is an aftermarket part designed to meet or exceed original specifications for performance and reliability. It provides a cost-effective solution without compromising on ignition timing, voltage output, or durability.
Do I need special tools to install this?
No special tools are required. Installation is plug-and-play and can be done with basic hand tools (like a socket wrench or screwdriver) to access and replace the unit.
How is a CDI unit different from an ignition coil?
The CDI unit is the "brain" that determines when to fire the spark plug, receiving a signal from the stator. It then releases a high-voltage charge to the ignition coil, which steps up the voltage further to create the spark. They are separate but related components in the ignition system.
Will this fix my engine's running problems?
If the issue is caused by a faulty CDI unit, this part should resolve it. However, poor engine performance can also result from other issues, such as a bad stator, faulty ignition coil, clogged carburetor, or old spark plugs. Proper diagnosis is key.
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.
Payment & Security
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