CDI Unit / Ignition Control Module for Yamaha Outboards

High-quality marine-grade aftermarket CDI ignition unit / power pack for selected Yamaha 9.9 HP, 13.5 HP and 15 HP 4-stroke outboard engines.

Designed for selected:

F9.9 / F13.5 / F15 4-Stroke Models

and supplied as an aftermarket replacement for Yamaha:

66M-85540-10

Selected applications are primarily from the earlier F9.9 / F13.5 / F15 4-stroke generation, with aftermarket application data particularly covering approximately 2002–2007.

Fits Selected Yamaha 4-Stroke Outboards

9.9 HP

Selected:

F9.9C

F9.9M

4-stroke applications.

Approximate aftermarket application data:

2002–2007

13.5 HP

Selected:

F13.5A

4-stroke applications.

Approximate aftermarket application data:

2002–2007

15 HP

Selected:

F15A

and selected F15 variants including:

F15A
F15E
F15M
F15P

depending on market and exact engine specification.

Approximate aftermarket application data:

2002–2007

Fitment Summary

HP	Selected Yamaha Models	Engine
9.9 HP	F9.9C / F9.9M	4 Stroke
13.5 HP	F13.5A	4 Stroke
15 HP	F15A / F15E / F15M / F15P	4 Stroke

Approximate Application Period

2002–2007

depending on the exact engine model and market.

⚠️ IMPORTANT

This does NOT mean every Yamaha 9.9 HP, 13.5 HP or 15 HP 4-stroke manufactured during these years uses this CDI.

Always identify the engine model and original CDI part number before ordering.

Replaces Yamaha Part Number

66M-85540-10

Also searchable as:

66M-85540-10-00
66M8554010
66M855401000

Related Yamaha CDI References

Depending on the exact engine model and production specification, this ignition family is also associated with:

66M-85540-00
66M-85540-00-00
66M-85540-01
66M-85540-01-00

⚠️ Important

Please use these additional numbers as cross-reference / identification information.

For the safest identification, check the exact number on your original CDI and your complete Yamaha engine model.

Additional Cross References

Selected aftermarket and related applications may also reference:

PAF15-07000500
F15-07000500

Selected Yamaha-derived Mercury / Mariner applications may also reference:

835401
8354011
835401T1

This listing is primarily advertised for the Yamaha applications above.

What Is the CDI Unit?

The CDI – Capacitor Discharge Ignition – unit is an important part of the outboard's ignition system.

It controls the ignition system and helps provide the correct ignition timing and spark operation required for the engine to run correctly.

A faulty CDI unit can be associated with symptoms such as:

No spark
Intermittent spark
Difficult starting
Misfiring
Engine cutting out
Loss of ignition when hot
Irregular engine operation

Important

These symptoms do NOT automatically mean the CDI unit is faulty.

Similar problems can be caused by other ignition or electrical components.

Proper diagnosis is recommended before replacing the CDI.

Product Features

Marine-grade aftermarket CDI unit
Ignition control module
Power pack
Suitable for selected Yamaha outboards
9.9 HP
13.5 HP
15 HP
4 Stroke
Selected F9.9
Selected F13.5
Selected F15
Replacement for 66M-85540-10
Direct replacement for compatible applications
OEM-style electrical connections for applicable engines
No assembly required
New aftermarket ignition component

⚠️ IMPORTANT – Check Before Ordering

Please do NOT order this CDI by horsepower or appearance alone.

Yamaha used different ignition-control modules across different generations of F9.9 and F15 outboards.

Before purchasing, please check:

Engine horsepower
Exact Yamaha model
4-stroke engine
Model designation
Engine serial number
Original CDI part number
Electrical connectors
Wiring configuration
Mounting arrangement

Ideally, match your original CDI to:

66M-85540-10

⚠️ Different Yamaha F9.9 / F15 Generations

Yamaha produced several generations of 9.9 HP and 15 HP 4-stroke engines.

The horsepower alone is NOT enough to identify the CDI.

For example, later F9.9 and F15 engine families can use completely different ignition/electrical components.

Please identify your exact model before ordering.

If your engine is not an applicable F9.9C / F13.5A / F15A-family model, do not assume this CDI will fit simply because the engine is 9.9 HP or 15 HP.

⚠️ Appearance Does Not Confirm Fitment

If the CDI unit looks the same as the one fitted to your engine, this does not always mean it is the correct part for your outboard.

Different Yamaha CDI units can look very similar externally but have different:

Internal specifications
Ignition characteristics
Wiring
Electrical connections
Applications

Always check the original part number and exact engine model.

Before Replacing Your CDI Unit

If your Yamaha has an ignition fault, we recommend checking the complete ignition system before installing a replacement CDI.

Check:

Ignition coils
Spark plugs
Spark plug caps and leads
Pulser / trigger components
Source / charging coil where applicable
Stop / kill circuit
Engine earth / ground connections
CDI wiring
Electrical connectors
Burnt or corroded terminals
Damaged wiring

A fault elsewhere in the ignition system can produce symptoms similar to a failed CDI unit.

Aftermarket Replacement Part

This is a high-quality marine-grade aftermarket replacement part.

It is not a genuine Yamaha component.

Yamaha and other OEM manufacturer names and part numbers are provided for identification and compatibility reference only.

The component is designed as a replacement for compatible applications using:

66M-85540-10

What's Included

1 × CDI Unit / Ignition Control Module

New aftermarket replacement component.

Buyer Responsibility

It is the buyer's responsibility to confirm compatibility before purchasing.

Please check:

Yamaha engine
Horsepower
4-stroke engine
Exact model designation
Engine serial number
Original CDI part number
Electrical connections

If you are unsure, please send SSI Marine:

Engine model + horsepower + complete serial number + clear picture of your existing CDI

Our technical team will be happy to help identify the correct ignition unit.

Why Buy From SSI Marine?

Marine-grade aftermarket & OEM-spec parts
Workshop-tested products
More than 10 years supplying and working with outboard engines
Same-day dispatch before 1 PM Monday–Friday
Royal Mail Tracked 24
UK stock
Collection available from Leigh, Greater Manchester
Technical support from experienced outboard specialists
Workshop open Monday–Friday, 9 AM–5 PM

9.9 HP 13.5 HP 15 HP Yamaha Outboard F9.9 F13.5 F15 4 Stroke CDI Unit 66M-85540-10