346-01303-0 is an engine holder gasket (also referred to as a base gasket or upper casing gasket) primarily used for Tohatsu and Nissan 2-stroke outboard motors.
It serves as the critical seal between the engine powerhead and the engine holder (upper casing), preventing water from entering the crankcase and ensuring exhaust gases are routed correctly.
OEM Part Number: 346-01303-0
Superseded Part Number: 346013030M / 346013031M (Use this number if searching for the latest genuine version).
Mercury Cross-Reference: 27-853987 / 27-853987001 (For International/Japanese origin Mercury models).
This gasket is specifically designed for 25HP and 30HP 2-stroke (2-cylinder) outboard models, including:
Tohatsu: M25C3, M30A4
Nissan: NS25C3, NS30A4