Yamaha Spring Retainer – 6S5-R2358-00-00

Tiny but tough, this steel “top hat” lives on the business end of every 1.8-liter Yamaha marine engine, locking each valve spring in perfect alignment so your SVHO or HO powerplant can spin cleanly past 7,000 rpm. Yamaha machines the retainer from heat-treated chromoly, then gives it a dark phosphate finish that shrugs off heat, oil acids, and the occasional salt-spray mist that sneaks past the cover.

Why it earns a place in your rebuild kit:

• OEM geometry mates precisely with factory keepers—no lapping, no guesswork.
• Lightweight profile keeps valve-train mass low, protecting cam lobes at sustained wide-open throttle.
• Phosphate coating resists corrosion far longer than bright-metal aftermarket copies.
• Direct fit for late-model 1.8 L jet-boat and WaveRunner engines—GP, FX, and F-series outboards that share the block.

Swapping a worn or pitted retainer during your winter teardown means rock-solid spring tension, cleaner idle, and crisper throttle snaps next season. For the price of a deck snack, you protect pistons, valves, and every hard-earned weekend on the water.