Head Gasket – Fits Johnson/Evinrude 120-140 HP (1985-1987) (Replaces OEM# 328623)

$22.95

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Product Details

This aftermarket Head Gasket – Fits Johnson/Evinrude 120-140 HP (1985-1987) is engineered for V4 2-stroke outboard engines, including 120 HP, 125 HP, 130 HP, and 140 HP models made between 1985–1987.

It serves as a direct replacement for OEM part number 328623 and interchanges with WSM 505-17 and PWC Engine 505-17 A.

Installs between the cylinder head and engine block to ensure a proper seal.
Made from OEM-specification gasket material for durability and performance.
Sold individually. Note: two gaskets are required per V4 engine.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Johnson/Evinrude (OEM)	328623
WSM	505-17
PWC Engine	505-17 A

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Johnson/Evinrude Models: This gasket fits the V4 engines listed below. Please verify your outboard's horsepower and year range.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Johnson/Evinrude	V4	120	2-Stroke	1985–1987	328623	2 gaskets required per engine
Johnson/Evinrude	V4	125	2-Stroke	1985–1987	328623	2 gaskets required per engine
Johnson/Evinrude	V4	130	2-Stroke	1985–1987	328623	2 gaskets required per engine
Johnson/Evinrude	V4	140	2-Stroke	1985–1987	328623	2 gaskets required per engine

Technical Specs

Product Type: Cylinder Head Gasket
Installation Location: Between cylinder head and block
Compatible Fuel: Gasoline (2-Stroke)
Material: OEM-specification gasket material
Product Dimensions: 31 in (L) x 15 in (W) x 0.5 in (H)
Package: Sold individually, 2 required per engine

What’s in the Box

1 x Head Gasket (Replaces OEM# 328623)

Installation Notes

Disconnect the battery and relieve any fuel system pressure.
Drain the engine coolant completely.
Remove the cylinder head cover and any other components obstructing access to the head bolts.
Loosen and remove the cylinder head bolts in the reverse sequence specified by the manufacturer's service manual.
Carefully lift the cylinder head from the engine block. Avoid prying, which can damage the mating surfaces.
Remove the old head gasket. Thoroughly clean both the cylinder head and engine block surfaces, ensuring they are perfectly flat and free of old gasket material, sealant, oil, and debris.
Place the new head gasket onto the engine block, confirming the correct orientation based on dowel pins or markings. Do not use sealant unless specifically required by the OEM manual.
Carefully lower the cylinder head back into place over the dowel pins and new gasket.
Install and tighten the head bolts in the sequence and to the torque specifications recommended by the engine manufacturer. This is critical for a proper, long-lasting seal.
Reassemble all previously removed components.
Refill the cooling system, reconnect the battery, and carefully start the engine. Check immediately for any coolant, oil, or fuel leaks.

Troubleshooting & FAQ

How do I know if my head gasket is failing?

Common signs of a failed head gasket include engine overheating, a noticeable loss of power or compression, milky-white engine oil (indicating coolant contamination), or excessive white smoke from the exhaust. A compression or leak-down test is the most reliable way to diagnose a bad gasket.

Do I need one or two gaskets for my V4 engine?

This part is sold as a single gasket. Because your Johnson/Evinrude V4 engine has two cylinder banks, you will need to purchase two gaskets for a complete engine overhaul.

Can I reuse my old head bolts?

It is strongly recommended to use new cylinder head bolts during installation. Head bolts are often torque-to-yield, meaning they stretch permanently when tightened and cannot provide the correct clamping force if reused. Reusing old bolts is a common cause of premature gasket failure.

Is sealant required for an installation?

These gaskets are designed to be installed dry on clean, flat surfaces. Do not use any additional sealants, adhesives, or gasket dressings unless explicitly instructed by your engine's service manual, as this can prevent a proper seal.

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

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