This is a brand new set of eighteen (18) Double Seal Crankcase Rings, enough to replace the stock Mercury OEM sealing rings on a 7 or 9-ring crank. These fit all V6 Mercury 2-stroke outboards (2.0 liters, 2.4 liters, and 2.5 liters) including all race, fishing and oiler cranks.
 
Upgrade Stock Sealing Rings
 
Mercury OEM crankcase sealing rings, including part numbers 78633, 67377, 673773, 9-8M0072093, and 39-673773, are crucial in maintaining the performance of V6 2-stroke outboard engines. These rings create an airtight seal around the crankshaft, preserving crankcase pressure vital for efficient engine operation.
 
In a 2-stroke engine, the crankcase acts as part of the air-fuel delivery system. The sealing rings ensure proper pressure differentials, aiding the scavenging process, where fresh air-fuel mixture replaces exhaust gases. They prevent leaks of gases, fuel, or oil, reducing power losses and ensuring smooth operation across all cylinders.
 
Our Double Sealing Rings
 
Our crankcase double seal rings have a flat ring face for the most efficient seal against the block surface. The rings are pre-engineered with a relief radius that will reduce the amount of drag against the crankshaft inside groove radius and improve sealing. Installation and chamfer diagrams are included with the crankshaft seal rings.
 
Contact Mike Hill at +1-714-697-1716 or mike@buckshotracing77.com with any questions.