Distributor Cap Gasket – Fits Mercury MerCruiser Thunderbolt IV & V Ignition (Replaces 27-805760)
Distributor Cap Gasket – Fits Mercury MerCruiser Thunderbolt IV & V Ignition (Replaces 27-805760) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Product Details
This Distributor Cap Gasket – Fits Mercury MerCruiser Thunderbolt IV & V Ignition (Replaces 27-805760) is a direct-fit replacement for MerCruiser stern drive and inboard engines from 1987–2001 using Thunderbolt IV and V ignition systems. It creates a critical seal to protect your distributor's internal components from moisture and contaminants.
It serves as a direct replacement for Mercury/MerCruiser part number 27-805760 and Mercury 805760.
- Mounts directly between the distributor body and cap.
- Essential for protecting Thunderbolt IV & V ignition systems.
- Designed for gasoline engine applications.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/MerCruiser | 27-805760 |
| Mercury | 805760 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This gasket fits a broad range of MerCruiser applications, including stern drives, inboards, ski, and racing engines. Please verify your specific model and year against the list.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 4.3L (2 BBL) GM 262 V-6 | - | 4-Stroke | 1993–1995 | 27-805760 | Gen II |
| MerCruiser | 4.3L (2 BBL) GM 262 V-6 | - | 4-Stroke | 1996 | 27-805760 | Gen II |
| MerCruiser | 4.3LX (4 BBL) GM 262 V-6 | - | 4-Stroke | 1993–1995 | 27-805760 | Gen II |
| MerCruiser | 4.3LX (4 BBL) GM 262 V-6 | - | 4-Stroke | 1996 | 27-805760 | Gen II |
| MerCruiser | 4.3L (2 BBL) GM 262 V-6 | - | 4-Stroke | 1996–1997 | 27-805760 | Gen+ |
| MerCruiser | 4.3LX (2 BBL) GM 262 V-6 | - | 4-Stroke | 1996–1997 | 27-805760 | Gen+ |
| MerCruiser | 4.3LH/4.3LXH (4 BBL) GM 262 V-6 | - | 4-Stroke | 1996–1997 | 27-805760 | Gen+ |
| MerCruiser | 4.3L (2 BBL) GM 262 V-6 | - | 4-Stroke | 1998 | 27-805760 | Gen+ |
| MerCruiser | 4.3LH (4 BBL) GM 262 V-6 | - | 4-Stroke | 1998 | 27-805760 | Gen+ |
| MerCruiser | 4.3L EFI (TBI) GM 262 V-6 | - | 4-Stroke | 1998–2001 | 27-805760 | Gen+ |
| MerCruiser | 4.3L CARB ALPHA/BRAVO | - | 4-Stroke | 2002-Up | 27-805760 | - |
| MerCruiser | 5.0L (2 BBL) GM 305 V-8 | - | 4-Stroke | 1988–1995 | 27-805760 | - |
| MerCruiser | 5.0L (2 BBL) GM 305 V-8 | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | 5.0LX (4 BBL) GM 305 V-8 | - | 4-Stroke | 1988–1995 | 27-805760 | - |
| MerCruiser | 5.0L CARB ALPHA/BRAVO | - | 4-Stroke | 2002-Up | 27-805760 | - |
| MerCruiser | 5.0L EFI GM 305 V-8 | - | 4-Stroke | 1999–2001 | 27-805760 | - |
| MerCruiser | 5.7L GM 350 V-8 | - | 4-Stroke | 1988–1995 | 27-805760 | - |
| MerCruiser | 5.7L (2 BBL) GM 350 V-8 | - | 4-Stroke | 1996–1997 | 27-805760 | - |
| MerCruiser | 5.7LX (4 BBL) GM 350 V-8 | - | 4-Stroke | 1996–1997 | 27-805760 | - |
| MerCruiser | 5.7L (2 BBL) GM 350 V-8 | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | 5.7L CARB ALPHA/BRAVO | - | 4-Stroke | 2002-Up | 27-805760 | - |
| MerCruiser | 5.7L EFI GM 350 V-8 | - | 4-Stroke | 1999–2001 | 27-805760 | - |
| MerCruiser | 350 MAG ALPHA GM 350 V-8 | - | 4-Stroke | 1987–1995 | 27-805760 | - |
| MerCruiser | 350 MAG ALPHA (4 BBL) GM 350 V-8 | - | 4-Stroke | 1996–1997 | 27-805760 | - |
| MerCruiser | 350 MAG MPI ALPHA/BRAVO | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | 454 MAG BRAVO (GEN V) GM 454 V-8 | - | 4-Stroke | 1992–1996 | 27-805760 | - |
| MerCruiser | 454 MAG BRAVO (GEN V) GM 454 V-8 | - | 4-Stroke | 1996–1997 | 27-805760 | - |
| MerCruiser | 7.4L BRAVO (GEN V) GM 454 V-8 | - | 4-Stroke | 1992–1996 | 27-805760 | - |
| MerCruiser | 7.4L BRAVO (GEN VI) GM 454 V-8 | - | 4-Stroke | 1996–1997 | 27-805760 | - |
| MerCruiser | 502 MAG BRAVO (GEN V) GM 502 V-8 | - | 4-Stroke | 1992–1993 | 27-805760 | - |
| MerCruiser | MX 6.2L MPI BRAVO | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | 5.7L MIE GM 350 V-8 | - | 4-Stroke | 1994–1997 | 27-805760 | - |
| MerCruiser | 5.7L CARB MIE | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | 7.4L MIE (LH) GEN V GM 454 V-8 | - | 4-Stroke | 1992–1996 | 27-805760 | - |
| MerCruiser | 7.4L MIE (LH) GEN VI GM 454 V-8 | - | 4-Stroke | 1996–1997 | 27-805760 | - |
| MerCruiser | 8.2L MIE GEN V GM 502 V-8 | - | 4-Stroke | 1993–1996 | 27-805760 | - |
| MerCruiser | 350 MAG MPI MIE | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | 350 MAG MPI HORIZON MIE | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | MX 6.2L MPI MIE | - | 4-Stroke | 1998-2001 | 27-805760 | - |
| MerCruiser | 350 MAG (SKI) GM 350 V-8 | - | 4-Stroke | 1991–1997 | 27-805760 | - |
| MerCruiser | 350 MAG MPI SKI (GEN+) GM 350 V-8 | - | 4-Stroke | 1998–2001 | 27-805760 | - |
| MerCruiser | 5.7L COMPETITION SKI GM 350 V-8 | - | 4-Stroke | 1987–1997 | 27-805760 | - |
| MerCruiser | 5.7L COMPETITION SKI (GEN+) GM 350 V-8 | - | 4-Stroke | 1998 | 27-805760 | - |
| MerCruiser | 5.7L CARB SKI | - | 4-Stroke | 2002-Up | 27-805760 | - |
| MerCruiser | 420 GM 454 V-8 | 420 | 4-Stroke | 1987–1989 | 27-805760 | Race Sterndrive |
| MerCruiser | 425 GM 454 V-8 | 425 | 4-Stroke | 1990–1992 | 27-805760 | Race Sterndrive |
| MerCruiser | 425 (GEN V) GM 454 V-8 | 425 | 4-Stroke | 1992–1993 | 27-805760 | Race Sterndrive |
| MerCruiser | 450 (GEN V) GM 454 V-8 | 450 | 4-Stroke | 1995–1996 | 27-805760 | Race Sterndrive |
| MerCruiser | 465 GM 502 V-8 | 465 | 4-Stroke | 1990–1992 | 27-805760 | Race Sterndrive |
| MerCruiser | 465 (GEN V) GM 502 V-8 | 465 | 4-Stroke | 1992–1994 | 27-805760 | Race Sterndrive |
| MerCruiser | 500 (GEN V) GM 502 V-8 | 500 | 4-Stroke | 1994–1996 | 27-805760 | Race Sterndrive |
| MerCruiser | 500 (GEN VI) GM 502 V-8 | 500 | 4-Stroke | 1997–1998 | 27-805760 | Race Sterndrive |
| MerCruiser | 500 (GEN+) GM 502 V-8 | 500 | 4-Stroke | 1999 | 27-805760 | Race Sterndrive |
| MerCruiser | 500 Bulldog GM 540 V-8 | 500 | 4-Stroke | 1990–1999 | 27-805760 | Race Sterndrive |
| MerCruiser | 525 SC GM 454 V-8 | 525 | 4-Stroke | 1991–1995 | 27-805760 | Race Sterndrive |
| MerCruiser | 525 SC (GEN V) GM 454 V-8 | 525 | 4-Stroke | 1992–1996 | 27-805760 | Race Sterndrive |
| MerCruiser | 525 SC - Gen VI | 525 | 4-Stroke | 1997–1999 | 27-805760 | Race Sterndrive |
| MerCruiser | 600 SC GEN IV & V GM 502 V-8 | 600 | 4-Stroke | 1991–1996 | 27-805760 | Race Sterndrive |
| MerCruiser | 600 SC Bobtail | 600 | 4-Stroke | 1998 | 27-805760 | Race Sterndrive |
| MerCruiser | 800 SC (GEN V) GM 572 V-8 | 800 | 4-Stroke | 1993–1998 | 27-805760 | Race Sterndrive |
| MerCruiser | 900 SC | 900 | 4-Stroke | 1997–1999 | 27-805760 | Race Sterndrive |
| MerCruiser | 900 SC Dry Sump | 900 | 4-Stroke | 2000-Up | 27-805760 | Race Sterndrive |
| MerCruiser | 350 (4 BBL) Gen+ Crate Engine | - | 4-Stroke | - | 27-805760 | All Serial Numbers |
| MerCruiser | 350 (4BBL) Crate Alpha | - | 4-Stroke | - | 27-805760 | Serial Number 1G800000 & Up |
| MerCruiser | 350 (4BBL) Crate Bravo | - | 4-Stroke | - | 27-805760 | Serial Number 1G800000 & Up |
| MerCruiser | 350 (4BBL) Crate Inboard | - | 4-Stroke | - | 27-805760 | Serial Number 1G800000 & Up |
| MerCruiser | 350 Alpha (4 BBL) Crate Engine | - | 4-Stroke | - | 27-805760 | All Serial Numbers |
| MerCruiser | 357 Alpha 4V | - | 4-Stroke | - | 27-805760 | Serial Number 1G400000 & Up |
| MerCruiser | 357 Mag Bravo 4V | - | 4-Stroke | - | 27-805760 | Serial Number 1G400000 & Up |
| MerCruiser | 383 Mag Bravo 4V | - | 4-Stroke | - | 27-805760 | Serial Number 1G480748 & Up |
| MerCruiser | 383 Mag Inboard 4V | - | 4-Stroke | - | 27-805760 | Serial Number 1G400000 & Up |
| MerCruiser | 540 Stroker 4V | - | 4-Stroke | - | 27-805760 | Serial Number 1G400000 & Up |
Technical Specs
- Product Type
- Distributor Cap Gasket
- Installation
- Mounts between distributor body and cap
- Fuel Type
- Gasoline
- Housing Material
- Gasket material (likely cork or composite)
- Dimensions
- 14 in × 11 in × 0.1 in (355.6 mm × 279.4 mm × 2.54 mm)
- Weight
- 0.02 lb (0.009 kg)
- Other Technical Attributes
- Designed for Thunderbolt IV & V ignition systems
What’s in the Box
- 1 x Gasket (27-805760)
Installation Notes
- Disconnect the boat's battery for safety.
- Carefully label and disconnect all spark plug wires and the coil wire from the distributor cap.
- Unlatch or unscrew the distributor cap and lift it off the distributor body.
- Remove the old distributor cap gasket. Thoroughly clean both mating surfaces on the cap and distributor housing, ensuring they are free of old material and debris.
- Place the new gasket onto the distributor housing, aligning it with the mounting holes.
- Reinstall the distributor cap, ensuring it is seated correctly on the gasket, and secure the latches or screws.
- Reconnect the spark plug and coil wires according to your labels.
- Reconnect the battery and start the engine to test for proper operation.
Troubleshooting & FAQ
How do I know if my distributor cap gasket is failing?
A failing gasket can allow moisture and contaminants into the distributor, leading to symptoms like engine misfires, rough idling, difficulty starting, and visible corrosion or carbon tracking on the inside of the cap.
Will this fit ignition systems other than Thunderbolt IV & V?
No, this gasket is specifically designed for Mercury MerCruiser engines equipped with Thunderbolt IV and Thunderbolt V ignition systems. It will not fit correctly on other systems.
What is the primary function of this gasket?
Its main purpose is to create a weather-tight seal between the distributor cap and the distributor housing. This prevents moisture, dust, oil vapor, and debris from contaminating the rotor, cap terminals, and ignition sensor, which could cause ignition failure.
Is any adhesive or sealant needed during installation?
Generally, no sealant is required. The gasket is designed to create a dry seal when the cap is properly tightened. Applying sealant can sometimes interfere with the fit or make future removal difficult. Always consult your engine’s service manual for specific recommendations.
How often should this gasket be replaced?
It is best practice to replace the distributor cap gasket anytime you replace the distributor cap or rotor. You should also replace it if you notice any signs of physical damage, brittleness, or leakage during inspection.
Can I reuse the old gasket after an inspection?
No, it is not recommended. Gaskets compress and conform to the surfaces they seal. Once removed, they rarely provide a reliable seal if reinstalled and are prone to leaking.
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
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
