CDI 174-2075K 2 - User Manual

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Installation and Troubleshooting Guide

This installation is to be completed by an Authorized Dealer or Professional Service

Technician. For questions regarding installation or warranty, call CDI Tech Support

at 866-423-4832. Do not return to the Dealer or Distributor where the part was purchased.

Contact CDI Electronics Directly for Return Material Authorization.

CDI Electronics, LLC • 353 James Record Road SW • Huntsville, AL 35824 USA

Web Support: www.cdielectronics.com • Tech Support: 1-866-423-4832 • Order Parts: 1-800-467-3371

Rev F • 6/19/2023 Page - 1 of 6 QF-358

CDI P/N: 174-2075K 2

This unit will replace the following P/N’s ONLY: 398-832075A3, A4, 398-9873A15, A19, A22, and A28.

Warning! This product is designed for installation by a professional marine mechanic. CDI Electronics cannot be held liable for

injury or damage resulting from improper installation, abuse, neglect, or misuse of this product.

This Stator is to be used as a replacement for the "RED" Mercury 16 Amp Stators. It is NOT a kit designed to replace the 398-5454,

398-8778, or 398-9710 series Stators.

Note: 174-2075K 2 requires a Voltage Regulator, DO NOT USE WITH A RECTIFIER ONLY.

Warning! Do not use this Stator with the 332-7778, 332-5772, 18495, or 19052 series Switch Boxes without the Adapter Module

because the voltage generated by the Ignition Charge coils of this Stator will destroy the Switch Boxes!

It is recommended that dielectric grease (i.e. CDI P/N: 991-9705) be used in the bullet nose connectors to help prevent corrosion.

Any sign of leakage out of the Ignition charge coils or bubbling around the battery charge windings indicate a bad Stator. Check for burned

marks on each pole. If a problem is found on the battery windings, we recommend the Voltage Regulator be closely checked. To replace

Stators with ring terminals, please use the bullet to ring adapters enclosed with this Stator.

INSTALLATION

1. Disconnect the Negative battery cable.

2. Disconnect the Stator wires from the CDM harness (or the Adapter Module for Switchbox applications), engine ground, and the Voltage

Regulator.

3. Remove the flywheel according to the service manual for your engine.

4. Mark the position of the mounting screws in relation to where the Stator wires come out of the old Stator.

5. Remove the old Stator.

6. Orient and install the new Stator (using a good thread-locker applied to the bolts) in the same position as the old Stator on the engine

and install the flywheel, following the service manual instructions.

7. Connect the new Stator Yellow wires to the Voltage Regulator ignoring any stripes on the Yellow wires of the Voltage Regulator as the

new Stator does not require the Yellow wires to be connected to a particular Voltage Regulator wire.

8. Connect the Green/White and White/Green Stator wires to the CDM harness (or the Adapter Module for Switchbox applications).

9. If installing this Stator on a 2 cylinder (30-40 HP) engine with CDM Ignition, you will need to use the provided barrel connector

depending on which connector you need. Remove the existing connector from the wire that will not connect to the TPM Module on your

engine. Solder or crimp the appropriate connector on the wire and connect the wire to the TPM Module.

10. Reinstall the flywheel according to the service manual for your engine.

11. Reconnect the Negative battery cable.

GENERAL TROUBLESHOOTING FOR CDM IGNITION SYSTEMS

HOW TO TEST THE ENGINE STOP CIRCUIT (KILL) FOR DC VOLTAGE:

1. DC voltage present on the kill circuit of the CDM Modules due to a faulty key switch, boat harness, or engine harness will severely

damage the CDM Module’s internal kill circuit. Disconnect the CDM wiring harness at the CDM’s on ALL OF THE CDM Modules at the

same time. Connect a Digital Multi Meter to the Black/Yellow Ignition Stop wires at the CDM’s by way of the plug connectors of the

CDM Harness. Use the Black/Yellow wires in reference to a known good engine ground (Black wire in CDM plug connector). Turn the

Ignition switch on and off several times. If at any time you see over 2 VDC on the kill wire(s), there is a problem with one or both

harnesses and/or the Ignition switch. The Ignition Stop wire should not be connected back to ANY CDM Module at any point until the

problem is corrected OR DAMAGE TO THE CDM MODULE’S WILL OCCUR!

NO SPARK ON ANY CYLINDER:

1. Disconnect each Black/Yellow stop wire from each CDM module and disconnect the RPM Limiter’s stop wire and retest. If the engine’s

Ignition now has spark, the stop circuit you just disconnected has a fault. Check the key switch, harness, RPM Limiter, and shift switch

(if present).

2. Disconnect the Yellow wires from the Voltage Regulator and retest. If the engine has spark, replace the Voltage Regulator.

3. Check the cranking RPM. A cranking speed of less than 250 RPM will not allow the system to spark properly. This can be caused by a

weak battery, dragging starter, bad battery cables, or a mechanical problem inside the engine.

4. Inspect the spark plug wires, boots, and spark plugs. Check for chafing on the wiring and harnesses.

5. Inspect and clean all engine and ignition ground connections.

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Summary

Installation Guide

Installation Procedure

Step-by-step instructions for installing the CDI stator unit on the engine.

CDM Ignition System Troubleshooting

Testing Engine Stop Circuit (Kill) for DC Voltage

Procedure to test DC voltage on the kill circuit to prevent CDM module damage.

No Spark on Any Cylinder

Steps to diagnose and resolve a complete lack of spark across all cylinders.

Intermittent Spark Troubleshooting

Diagnosing and fixing intermittent or missing spark on specific cylinders.

High Speed Misfire and Hole Shot Issues

Troubleshooting performance issues like misfires and poor acceleration at high speeds.

2 Cylinder CDM Ignition Specifics

Specific troubleshooting steps and tests for 2-cylinder CDM ignition systems.

3 Cylinder CDM Ignition Specifics

Specific troubleshooting steps and tests for 3-cylinder CDM ignition systems.

4 Cylinder CDM Ignition Specifics

Specific troubleshooting steps and tests for 4-cylinder CDM ignition systems.

Switchbox Ignition System Troubleshooting

Switchbox Kill Circuit Testing

Procedure to test DC voltage on the kill circuit to prevent switchbox damage.

Switchbox No Spark Troubleshooting

Steps to diagnose and resolve a complete lack of spark with switchbox systems.

2 Cylinder Switchbox Ignition Specifics

Specific troubleshooting steps and tests for 2-cylinder switchbox ignition systems.

3 Cylinder Switchbox Ignition Specifics

Specific troubleshooting steps and tests for 3-cylinder switchbox ignition systems.

4 Cylinder Switchbox Ignition Specifics

Specific troubleshooting steps and tests for 4-cylinder switchbox ignition systems.

General System Diagnostics and Maintenance

Engine Performance Issues

Troubleshooting misfires and weak performance at higher engine speeds.

Engine Will Not Stop (Kill) Troubleshooting

Diagnosing why the engine fails to shut off when the ignition is turned off.

Battery Charging System Troubleshooting

Diagnosing and resolving problems related to battery charging or overcharging.

Tachometer Signal Testing

Procedures for testing tachometer signals and related components.

Overcharging Battery Diagnosis

Steps to identify and resolve battery overcharging conditions.

Summary

Installation Guide

Installation Procedure

Step-by-step instructions for installing the CDI stator unit on the engine.

CDM Ignition System Troubleshooting

Testing Engine Stop Circuit (Kill) for DC Voltage

Procedure to test DC voltage on the kill circuit to prevent CDM module damage.

No Spark on Any Cylinder

Steps to diagnose and resolve a complete lack of spark across all cylinders.

Intermittent Spark Troubleshooting

Diagnosing and fixing intermittent or missing spark on specific cylinders.

High Speed Misfire and Hole Shot Issues

Troubleshooting performance issues like misfires and poor acceleration at high speeds.

2 Cylinder CDM Ignition Specifics

Specific troubleshooting steps and tests for 2-cylinder CDM ignition systems.

3 Cylinder CDM Ignition Specifics

Specific troubleshooting steps and tests for 3-cylinder CDM ignition systems.

4 Cylinder CDM Ignition Specifics

Specific troubleshooting steps and tests for 4-cylinder CDM ignition systems.

Switchbox Ignition System Troubleshooting

Switchbox Kill Circuit Testing

Procedure to test DC voltage on the kill circuit to prevent switchbox damage.

Switchbox No Spark Troubleshooting

Steps to diagnose and resolve a complete lack of spark with switchbox systems.

2 Cylinder Switchbox Ignition Specifics

Specific troubleshooting steps and tests for 2-cylinder switchbox ignition systems.

3 Cylinder Switchbox Ignition Specifics

Specific troubleshooting steps and tests for 3-cylinder switchbox ignition systems.

4 Cylinder Switchbox Ignition Specifics

Specific troubleshooting steps and tests for 4-cylinder switchbox ignition systems.

General System Diagnostics and Maintenance

Engine Performance Issues

Troubleshooting misfires and weak performance at higher engine speeds.

Engine Will Not Stop (Kill) Troubleshooting

Diagnosing why the engine fails to shut off when the ignition is turned off.

Battery Charging System Troubleshooting

Diagnosing and resolving problems related to battery charging or overcharging.

Tachometer Signal Testing

Procedures for testing tachometer signals and related components.

Overcharging Battery Diagnosis

Steps to identify and resolve battery overcharging conditions.

The CDI P/N: 174-2075K 2 is an installation and troubleshooting guide for a Stator designed for marine ignition systems. This Stator is specifically intended as a replacement for "RED" Mercury 16 Amp Stators, with part numbers 398-832075A3, A4, 398-9873A15, A19, A22, and A28. It is crucial to note that this Stator is NOT a kit designed to replace the 398-5454, 398-8778, or 398-9710 series Stators.

Function Description:

The primary function of this Stator is to generate voltage for the ignition and charging systems of an outboard marine engine. It works in conjunction with a Voltage Regulator and, for Switchbox applications, requires an Adapter Module. The Stator produces both ignition charge voltage and battery charge voltage.

Important Technical Specifications:

Part Number: CDI P/N: 174-2075K 2
Compatibility: Replaces specific Mercury 16 Amp Stators (398-832075A3, A4, 398-9873A15, A19, A22, A28).
Voltage Regulator Requirement: Requires a Voltage Regulator; DO NOT USE WITH A RECTIFIER ONLY.
Switchbox Compatibility Warning: Must be used with an Adapter Module when paired with 332-7778, 332-5772, 18495, or 19052 series Switch Boxes. Failure to use the Adapter Module will result in destruction of the Switch Boxes due to high ignition charge coil voltage.
Stator Resistance (CDM Ignition):
- White/Green to Green/White (Stator): OEM Ohms 500-700 Ω, CDI Ohms 400-550 Ω.
Stator DVA (CDM Ignition):
- White/Green to Green/White (Stator): DVA (Connected) 180-400 V, DVA (Disconnected) 200-400 V.
Trigger DVA (CDM Ignition - 2 Cylinder):
- Purple (#1 Trigger) to Engine Gnd: DVA (Connected) 0.5-1.5 V, DVA (Disconnected) 5 V or more.
- White (#2 Trigger) to Engine Gnd: DVA (Connected) 0.5-1.5 V, DVA (Disconnected) 5 V or more.
Trigger DVA (CDM Ignition - 3 Cylinder):
- Purple (#1 Trigger) to Engine Gnd: DVA (Connected) 1 V Minimum, DVA (Disconnected) 1 V Minimum.
- White (#2 Trigger) to Engine Gnd: DVA (Connected) 1 V Minimum, DVA (Disconnected) 1 V Minimum.
- Brown (#3 Trigger) to Engine Gnd: DVA (Connected) 1 V Minimum, DVA (Disconnected) 1 V Minimum.
Trigger DVA (CDM Ignition - 4 Cylinder):
- Purple (#1 Trigger) to Engine Gnd: DVA (Connected) 1 V Minimum, DVA (Disconnected) 1 V Minimum.
- White (#2 Trigger) to Engine Gnd: DVA (Connected) 1 V Minimum, DVA (Disconnected) 1 V Minimum.
- Brown (#3 Trigger) to Engine Gnd: DVA (Connected) 1 V Minimum, DVA (Disconnected) 1 V Minimum.
- Blue (#4 Trigger) to Engine Gnd: DVA (Connected) 1 V Minimum, DVA (Disconnected) 1 V Minimum.
Trigger Resistance (Switchbox Ignition - 2, 3, 4 Cylinder):
- Purple (#1 Trigger) to White (#2 Trigger): 0.8-1.4K Ω.
- Brown (#3 Trigger) to White/Black or Black (#4 Trigger): 0.8-1.4K Ω.
Trigger DVA (Switchbox Ignition - 2, 3, 4 Cylinder):
- Purple (#1 Trigger) to White (#2 Trigger): DVA (Connected) 4 V Minimum, DVA (Disconnected) 4 V Minimum.
- Brown (#3 Trigger) to White/Black or Black (#4 Trigger): DVA (Connected) 4 V Minimum, DVA (Disconnected) 4 V Minimum.
- Trigger to Engine Gnd: DVA (Connected) 1 V Minimum.
Battery Charging DVA (Stator Yellow wires):
- Connected to Voltage Regulator: 8-25 DVA at idle.
- Disconnected from Voltage Regulator: 17-50 DVA at idle.
Tachometer Signal DVA (Voltage Regulator Gray wire):
- 8 DVA or more at 800-1,000 RPM.

Usage Features:

Professional Installation: This product is designed for installation by a professional marine mechanic. CDI Electronics is not liable for injury or damage from improper installation.
Dielectric Grease: Recommended for bullet nose connectors to prevent corrosion (CDI P/N: 991-9705).
Stator Orientation: The new Stator should be installed in the same position as the old Stator on the engine.
Wiring Connections:
- Yellow Stator wires connect to the Voltage Regulator (stripes on Regulator wires can be ignored).
- Green/White and White/Green Stator wires connect to the CDM harness (or Adapter Module for Switchbox applications).
- For 2-cylinder (30-40 HP) engines with CDM Ignition, a provided barrel connector may be needed for specific wire connections to the TPM Module.
Troubleshooting Guides: Comprehensive guides are provided for CDM Ignition Systems and Switchbox Ignition Systems, covering:
- Engine Stop Circuit (Kill) DC Voltage Test.
- No Spark on Any Cylinder.
- Intermittent Spark or No Spark on One or More Cylinders.
- High Speed Misfire or Weak Hole Shot.
- Engine Will Not Stop (Kill).
- Battery Charging Issues.
- Tachometer Tests.
- Overcharging Battery.

Maintenance Features:

Visual Inspection: Regularly inspect Stator for leakage from ignition charge coils, bubbling around battery charge windings, or burned marks on poles, which indicate a faulty Stator.
Ground Connections: Ensure all engine and ignition ground connections are clean and tight.
Battery Maintenance:
- Use a single (NOT more than one) 850+ CCA dual purpose or cranking/starting non-maintenance-free (lead-acid flooded cell with vent caps) battery for outboards.
- NEVER use maintenance-free batteries in outboard applications as they shorten lifespan and can lead to Voltage Regulator failure.
- Check battery connections for tightness and corrosion; avoid wing nuts.
Voltage Regulator Check: If battery charging issues persist or DVA readings are out of spec, the Voltage Regulator should be closely checked and replaced if defective.
Stator Rotation: For high-speed misfire or weak hole shot, rotating the Stator one bolt hole in either direction can sometimes resolve the issue.
Spark Plug Wires/Boots/Plugs: Inspect for chafing and proper condition.
Cranking RPM: Ensure cranking speed is at least 250 RPM for proper spark.
CDM Module Testing: Procedures for testing CDM module resistance and isolating faulty modules are provided.
Trigger Testing: Procedures for DVA testing of Trigger wires are included, noting that resistance tests are not possible for Triggers with built-in Bias circuits.
Wiring Harnesses: Check for proper contact, chafing, and corrosion in all wiring and harnesses.