390510 OMC PISTON-RING SET .030

Genuine OEM piston ring set (part #390510, .030 oversize) engineered for OMC (Outboard Marine Corporation) outboard motors from Johnson and Evinrude. Sized for a .030-inch overbore, these rings seal the piston against the cylinder wall to maintain compression and control lubrication. A direct-fit set for rebuilding your OMC powerhead.