PRODUCT DETAILS
CDI UNIT
CDI Unit / Ignition Module for Yamaha F9.9B Outboards
High-quality marine-grade aftermarket CDI ignition unit for selected Yamaha F9.9B 9.9 HP 4-stroke outboard engines.
Designed specifically for the earlier Yamaha F9.9B engine family identified by the 6G9 model/prefix.
FOR 6G9 ENGINES ONLY
Designed as a replacement for Yamaha CDI references including:
6G9-85540-20 / 21 / 22 / 29
Fits Selected Yamaha Outboards
9.9 HP
Yamaha F9.9B
- 9.9 HP
- 4 Stroke
- Selected F9.9B applications
- 6G9 engine family / prefix only
⚠️ VERY IMPORTANT
This CDI should NOT be selected simply because your Yamaha outboard is an F9.9 or 9.9 HP 4-stroke.
Yamaha produced several generations of F9.9 outboards using different CDI / ignition components.
Replaces Yamaha Part Numbers
- 6G9-85540-20
- 6G9-85540-20-00
- 6G9-85540-21
- 6G9-85540-21-00
- 6G9-85540-22
- 6G9-85540-22-00
- 6G9-85540-29
- 6G9-85540-29-00
Searchable Without Hyphens
- 6G98554020
- 6G9855402000
- 6G98554021
- 6G9855402100
- 6G98554022
- 6G9855402200
- 6G98554029
- 6G9855402900
OEM manufacturer names and part numbers are provided for identification and compatibility reference only.
⚠️ 6G9 ENGINE FAMILY ONLY
PLEASE CHECK BEFORE ORDERING
This listing is specifically for selected Yamaha F9.9B engines from the 6G9 family.
Look for:
6G9
in your engine identification / model information and compare the original CDI part number.
Do NOT order this CDI for a different F9.9 engine generation simply because:
- Your engine is Yamaha
- Your engine is 9.9 HP
- Your engine is 4 Stroke
- Your engine is marked F9.9
- The CDI looks similar
The exact engine family and CDI reference must be checked.
Different Yamaha F9.9 Generations
Yamaha has produced several different 9.9 HP 4-stroke engine families.
For example:
This Listing
F9.9B – 6G9 Family
CDI references:
6G9-85540-20 / 21 / 22 / 29
Other F9.9 Models
Later or different F9.9 engine families can use completely different CDI / ignition-control modules.
These parts are NOT interchangeable simply because the horsepower is the same.
What Is the CDI Unit?
The CDI – Capacitor Discharge Ignition – unit is an important component of the outboard's ignition system.
It controls the ignition operation required for the engine to produce spark at the correct time.
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 that the CDI is faulty.
Similar symptoms can be caused by other ignition or electrical components.
Proper diagnosis is recommended before replacing the CDI unit.
Product Features
- Marine-grade aftermarket CDI unit
- Ignition control module
- Suitable for selected Yamaha outboards
- 9.9 HP
- F9.9B
- 4 Stroke
- 6G9 engine family
- Replacement for 6G9-85540-20
- Replacement for 6G9-85540-21
- Replacement for 6G9-85540-22
- Replacement for 6G9-85540-29
- Direct replacement for compatible applications
- No assembly required
- New aftermarket ignition component
⚠️ IMPORTANT – Check the Original CDI Number
For the safest identification, compare the part number on your original CDI.
It should correspond with one of the following:
6G9-85540-20
6G9-85540-21
6G9-85540-22
6G9-85540-29
If your original CDI carries a completely different Yamaha prefix, please contact us before ordering.
⚠️ 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 while having different:
- Internal specifications
- Ignition characteristics
- Wiring
- Electrical connectors
- Applications
Always check the engine identification and original part number.
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
- Source / charging coil
- Pulser / trigger components
- 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 names and OEM part numbers are provided for identification and compatibility reference only.
The component is designed as a replacement for compatible Yamaha F9.9B 6G9-family applications using the CDI references listed above.
What's Included
1 × CDI Unit / Ignition Module
New aftermarket replacement component.
Buyer Responsibility
It is the buyer's responsibility to confirm compatibility before purchasing.
Please check:
- Yamaha engine
- 9.9 HP
- F9.9B
- 4 Stroke
- 6G9 engine family / prefix
- Exact model information
- Original CDI part number
- Electrical connections
If you are unsure, please send SSI Marine:
A picture of the engine identification plate + a clear picture of the existing CDI and its part number
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
SHIPPING & DELIVERY
Delivery & Returns Policy
Delivery
Standard Delivery
- £6: Royal Mail Tracked 24 Service
- £3.99: Large Letter - Royal Mail 1st Class Post (Untracked)
We offer free delivery on all orders over £150 (excludes outboard engines).
Orders placed before 1:00 PM (Monday-Friday) are usually dispatched the same working day.
Most parcels are delivered within 24 hours, but please allow extra time for courier delays that may occur outside our control.
For outboard engines, please contact us for a delivery quote.
Important: Please ensure your shipping address is correct before completing checkout. SSI Marine is not responsible for parcels sent to an incorrect address provided by the buyer.
Tracking Your Order
Once your order has been dispatched, you will receive a tracking number via email (after 5 PM on the day of dispatch).
Tracking is available only for parcels sent via Royal Mail Tracked 24.
Large Letter orders are sent via Royal Mail 1st Class Post (untracked).
Returns
We accept returns of unused and undamaged items within 30 days of purchase.
Returned items must be in sellable condition and include the original packaging.
Please do not tape, label, or write directly on the product's original box.
Important: Do not return items in their original product boxes only, they must be placed inside a protective outer box or bag. Parcels returned like the example below will be subject to a 20% restocking fee.
Return shipping costs are the customer's responsibility.
Please include your order details and reason for return inside the parcel.
Refunds
Refunds are issued for the item purchase price only (shipping costs are non-refundable).
All refunds will be made using the same payment method as your original order.
Items returned in poor condition or without proper packaging may incur a 20% restocking fee.
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