1989-2004 Kawasaki KX500 Billet 4140 Chromoly Power Valve Drums

The search for the ultimate KX500 power valve solution is over. While original OEM drums are increasingly hard to find and prone to wear, many aftermarket replacements are made from aluminum—a material that simply isn't up to the task in a high-friction, high-heat exhaust port. Our drums are built to be the final set you ever buy.

CNC-machined from hardened 4140 Chromoly steel, these drums are engineered to handle the brutal environment of the KX500. They don't just replace the factory parts; they completely outclass both the OEM units and the weaker aluminum versions on the market in terms of strength and longevity.

Built to Outlast the Bike

• Better than Aluminum: Unlike aluminum aftermarket drums that can gall, ovalize, or wear down prematurely, our hardened steel construction provides the surface hardness required for permanent durability.

• Indestructible Design: These drums are significantly stronger than the stock cast units. They are designed to withstand the constant hammering of a 500cc two-stroke without ever fatiguing or wearing out.

• Precision Machined: Every drum is CNC-cut to exacting tolerances to ensure smooth, consistent power valve operation throughout the entire RPM range.

• The Final Upgrade: This is a "set it and forget it" part. Install them once and never worry about power valve drum failure again.

Fitment & Specs

• Models: Kawasaki KX500 (1989–2004)

• Right Side Drum: Replaces OEM 12005-1109

• Left Side Drum: Replaces OEM 12005-1110

• Quantity: Sold as a pair

• Material: Hardened 4140 Chromoly Steel

• Origin: Designed and Machined in the USA

Stop Settling for Weak Links. Most power valve failures stem from worn-out drum surfaces, gear teeth or center valve grooves. By moving to hardened 4140 steel, you’re eliminating the weak point in your top end and choosing a material that will never wear out.