Replacement O-Ring Kit For The KRP4300 KRP4320

The Replacement O-Ring Kit For The KRP4300 KRP4320 from King Racing Products is an essential maintenance component for fuel system integrity on high-performance marine engines. Whether you're running a competition boat, a commercial fishing vessel, or a weekend cruiser, fuel filter seals degrade over time due to heat cycles, pressure fluctuations, and exposure to ethanol-blended fuels. This kit provides the matched pair of o-rings in 6 AN and 12 AN sizes, engineered to restore a watertight seal and prevent fuel leaks that compromise both safety and engine performance.

Constructed from durable synthetic rubber, these o-rings are formulated to resist degradation from modern fuel blends and maintain elasticity across the temperature ranges experienced in marine engine compartments. The 6 AN and 12 AN designation refers to the AN (Army-Navy) fitting standard, a critical sizing specification that ensures the rings compress properly against the KRP4300 and KRP4320 fuel filter housings without over-tightening or under-sealing. Proper o-ring compression is essential—too loose and fuel weeps past the seal; too tight and the rubber pinches, creating micro-leaks that develop into major failures. King Racing Products has engineered these rings to the exact durometer (hardness) required for consistent, long-term reliability in both gasoline and light fuel applications common to recreational and professional boating.

Anglers and boaters who maintain their own fuel systems will appreciate the straightforward installation: simply replace the old, compressed o-rings with these new ones during routine fuel filter service. This kit is ideal for season opener prep, post-storage maintenance, or whenever fuel system inspection reveals a slow weep around the filter bowl or top housing. At 0.03 lbs and compact dimensions, it's lightweight enough to keep spare kits in the boat's maintenance locker. Compatible with King Racing Products KRP4300 and KRP4320 fuel filters, this replacement kit restores factory seal performance and eliminates the guesswork of sourcing individual AN-sized o-rings from generic suppliers.