Rotor Assembly – Fits MerCruiser V6 Engines with Thunderbolt IV & V HEI Ignition (Replaces 13524A6)
Rotor Assembly – Fits MerCruiser V6 Engines with Thunderbolt IV & V HEI Ignition (Replaces 13524A6) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Rotor Assembly – Fits MerCruiser V6 Engines with Thunderbolt IV &am...
Product Details
This Rotor Assembly – Fits MerCruiser V6 Engines with Thunderbolt IV & V HEI Ignition (Replaces 13524A6) is designed for MerCruiser V6 engines (175-225 HP, 4.3L) manufactured between 1988 and 1998, specifically those equipped with Thunderbolt IV and V HEI ignition systems. It serves as a crucial component for proper ignition timing and engine performance.
This assembly provides a direct interchange for OEM and aftermarket parts, including Mercury/Quicksilver 13524A6, Sierra 18-5432, GLM 72890, and BPI 72890.
- Installs as a direct replacement inside the distributor assembly.
- Designed for gasoline-fueled marine engines.
- The kit includes both the rotor and trigger wheel for a complete refresh.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/Quicksilver | 13524A6 |
| Sierra | 18-5432 |
| GLM | 72890 |
| BPI | 72890 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Designed for various MerCruiser V6 engines produced between 1987 and 1998 with Thunderbolt IV & V HEI ignition systems.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 4.3L (2 BBL.) GM 262 V-6 | 175 | 4-Stroke | 1988–1992 | 13524A6 | 175 HP version |
| MerCruiser | 4.3LX (4 BBL.) GM 262 V-6 | 205 | 4-Stroke | 1988–1992 | 13524A6 | 205 HP version |
| MerCruiser | 4.3L (2 BBL.) GM 262 V-6 | 175 | 4-Stroke | 1987 | 13524A6 | |
| MerCruiser | 205 (4 BBL.) GM 262 V-6 | 205 | 4-Stroke | 1987 | 13524A6 | |
| MerCruiser | 4.3L (GEN II) (2 BBL.) GM 262 V-6 | 175-205 | 4-Stroke | 1992–1993 | 13524A6 | Alpha One Engine |
| MerCruiser | 4.3L (GEN II) (2 BBL.) GM 262 V-6 | 175-205 | 4-Stroke | 1993–1995 | 13524A6 | Alpha One Engine (GEN II) |
| MerCruiser | 4.3L (GEN II) (2 BBL.) GM 262 V-6 | 175-205 | 4-Stroke | 1996 | 13524A6 | Alpha/Bravo (GEN II) |
| MerCruiser | 4.3LX (GEN +) (2 BBL.) GM 262 V-6 | 175-205 | 4-Stroke | 1996–1997 | 13524A6 | Alpha and Bravo (GEN +) |
| MerCruiser | 4.3LH (GEN +) (4 BBL.) GM 262 V-6 | 205-225 | 4-Stroke | 1998 | 13524A6 | Alpha/Bravo (262 CID - GEN +) |
| MerCruiser | 4.3L EFI (GEN+) TBI GM 262 V-6 | 175-225 | 4-Stroke | 1996–1998 | 13524A6 | EFI Alpha/Bravo |
| MerCruiser | 4.3L CARB ALPHA/BRAVO | 175-205 | 4-Stroke | 1996–1998 | 13524A6 | |
| MerCruiser | 4.3L (GEN +) (4BBL) | 205-225 | 4-Stroke | 1996–1998 | 13524A6 | Alpha 4V (Reman) |
Technical Specs
- Product Type
- Rotor and Trigger Wheel Assembly
- Installation
- Direct replacement for distributor assembly
- Fuel Type
- Gasoline
- Connection
- Fits onto distributor shaft
- Housing Material
- Plastic/Metal composite
- Housing Color
- Black
- Dimensions
- 9.0" H x 8.0" W x 10.0" L
- Fitting Type
- Distributor - Thunderbolt IV & V HEI Ignition Systems
- Other Technical Attributes
- Used with Distributor Assembly – Thunderbolt IV & V
What’s in the Box
- 1 x Rotor (MerCruiser 13524A4/GLM 71070)
- 1 x Trigger Wheel (MerCruiser 11351/GLM 71501)
Installation Notes
- Ensure the engine is off and cool. Disconnect the battery's negative terminal for safety.
- Remove the distributor cap by releasing the hold-down clips or screws. Set it aside without disconnecting spark plug wires.
- Note the exact orientation of the existing ignition rotor's metal contact. Take a photo if necessary.
- Pull the old rotor straight up off the distributor shaft. It may require firm but steady pressure.
- Remove the old trigger wheel located beneath the rotor.
- Install the new trigger wheel, ensuring it is properly seated.
- Install the new rotor onto the shaft, aligning its metal contact to the same position as the old one. Ensure it clicks firmly into place.
- Reinstall the distributor cap, making sure it is correctly aligned and secured.
- Reconnect the battery terminal. Start the engine to verify proper operation and check ignition timing if necessary.
Troubleshooting & FAQ
How do I know if this rotor assembly fits my engine?
This part is specifically for MerCruiser V6 4.3L engines made from 1988–1998 that are equipped with Thunderbolt IV or V HEI ignition systems. The most reliable way to confirm fitment is to match the OEM part number 13524A6. Please check your service manual or existing part before ordering.
What are the signs of a failing ignition rotor?
Symptoms of a faulty rotor or trigger wheel include engine misfires, rough idling, hesitation during acceleration, difficulty starting, or a no-start condition. A visual inspection may reveal cracks, burn marks, or heavy corrosion on the rotor's metal contact point.
Is this a complete distributor?
No, this product is not a full distributor. It is a replacement rotor and trigger wheel assembly that fits inside your existing distributor housing. It is a key part of a tune-up for engines with Thunderbolt IV & V ignition.
What is the difference between Thunderbolt IV and V ignition?
Both are HEI (High Energy Ignition) systems used by MerCruiser, but they have internal differences. However, this rotor assembly is designed to be compatible with both Thunderbolt IV and V systems on the specified V6 engines.
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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