Description

The Yanmar 121450-11310 is a genuine OEM bonnet / valve cover gasket for select Yanmar marine diesel engines. Current parts references identify this number as Gasket, Bonnet or Rocker Cover Gasket, and current fitment references consistently tie it to the 3GM engine family.

This gasket seals the valve cover to help prevent oil seepage and maintain proper sealing at the rocker cover. Current marine parts references specifically associate 121450-11310 with 3GM, 3GMF, 3GM30, 3GM30F, and 3GMD / 3GM30D applications.

Key Features

• Genuine Yanmar OEM gasket
• OEM part number: 121450-11310
• Current part descriptions: Gasket, Bonnet / Rocker Cover Gasket
• Designed for select Yanmar 3GM-series engines
• Valve cover / rocker cover sealing gasket.

Engine Compatibility
Current supported references associate 121450-11310 with Yanmar 3GM, 3GMF, 3GM30, 3GM30F, and 3GMD / 3GM30D engines.

Serial Number Fitment Notice
Fitment should be verified by engine model and serial number before ordering. Matching by OEM part number 121450-11310 remains the safest method.

When This Part Needs Replacement
Replace the gasket if there is oil leakage around the valve cover, if the gasket is flattened, brittle, cracked, or damaged during service. This guidance is based on the function of a valve cover gasket; the cited sources primarily confirm part identity and fitment.

Installation Notes
Install only where 121450-11310 is specified. Confirm the existing gasket matches the rocker cover layout before installation, and inspect the sealing surfaces during service.

Alternate / Superseded Part Numbers when applicable
No superseded OEM number was confirmed in the reviewed sources. The supported OEM part number is 121450-11310.

Parts Desk Insight
Valve cover gaskets are simple parts, but on older Yanmar 3GM-series engines they are a common service item whenever the rocker cover comes off. Replacing the gasket during service is a small step that helps avoid annoying oil seepage later.

Shipping
Shipping: Ships same or next day for fast Canada wide shipping.