688-85540-16 CDI Unit Assembly for Yamaha 90 ETL/XL C75 TLR E75 MLH 75A E(M/H/D/T)L 80A E(M)TOL/UL C85 TLR CV85 ETL 85A ET(D)L/X 90 TL/XLR 90A ETOL/XL | JLM Marine

CDI Unit Assembly – Fits Yamaha 75HP–90HP Outboards (1984–1996)

This aftermarket CDI Unit Assembly is engineered to replace OEM part numbers 688-85540-15 and 688-85540-16 for Yamaha outboard engines ranging from 75HP to 90HP across multiple model series produced between 1984 and 1996. Designed to deliver reliable ignition performance, this CDI box provides the precise energy needed to ignite fuel and stabilize the flame, ensuring smooth engine operation across a wide range of conditions.

This unit is a direct replacement for Yamaha part numbers 688-85540-15 and 688-85540-16, offering broad compatibility with C75, E75, 75A, 80A, C85, CV85, 85A, and 90/90A series engines. Built from durable plastic materials and equipped with plug-and-play connectors, it ensures straightforward installation with low heat generation and reduced power consumption.

• Plug-and-play design: Pre-wired connectors for direct installation without modifications
• Low heat & power consumption: Engineered for efficient, reliable ignition performance
• Durable construction: High-quality plastic housing ensures long-lasting durability in marine environments

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket sources.

Compatible Engine Models

Confirm your engine model/year in the table below. For Yamaha owners, here's a guide to help you identify your engine's serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.

Technical Specifications

Package Contents

Your package includes:

• 1 × CDI Igniter Unit Assembly

The package contains all components shown in the product images.

Installation Guide

1. Disconnect the battery: Always disconnect the negative terminal before working on the ignition system to prevent electrical shock or accidental sparking.
2. Locate the existing CDI unit: Refer to your engine's service manual or wiring diagram to identify the CDI box mounting location.
3. Disconnect the wiring harness: Carefully unplug all connectors from the old CDI unit. Note the orientation and position of each connector.
4. Remove the mounting hardware: Unscrew or unclip the old CDI unit from its bracket or mounting surface.
5. Install the new CDI unit: Position the replacement unit in the same location and secure it with the original mounting hardware.
6. Reconnect all connectors: Plug each connector into the corresponding terminal on the new CDI unit, ensuring a firm, secure fit.
7. Reconnect the battery: Reattach the negative battery terminal.
8. Test engine operation: Start the engine and verify smooth idle, acceleration, and overall ignition performance. If issues persist, recheck all connections.

Troubleshooting & FAQ

Q: How do I confirm this CDI unit fits my Yamaha engine?
A: Cross-reference your engine model and year with the compatibility table above. Also verify that your current CDI unit has part number 688-85540-15 or 688-85540-16 stamped on its casing.

Q: What are the signs that my CDI unit is failing?
A: Common symptoms include difficulty starting, misfiring, rough idle, loss of power at high RPM, or the engine cutting out intermittently. If ignition coils and spark plugs are in good condition but problems persist, the CDI may be faulty.

Q: How often should I replace the CDI unit?
A: CDI units typically last many years under normal operating conditions. Replace only when you experience ignition failure or erratic performance that cannot be traced to spark plugs, coils, or wiring issues.

Q: Can I install this CDI unit myself?
A: Yes, installation is straightforward with basic hand tools and a plug-and-play design. However, if you are unfamiliar with marine electrical systems, professional installation is recommended to ensure safety and proper function.

Q: Is this an OEM or aftermarket part?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.