ProX Piston Kit (44.45mm Size A) 01.4022.A - Kawasaki KX65 / Suzuki RM65 2000-2026

Product Description

The ProX 01.4022.A Piston Kit delivers crisp throttle response and dependable top-end compression for high-revving 65cc two-stroke race engines. Screaming mini motocross bikes place immense heat and cyclic load on the piston crown and ring pack, leading to ring blow-by, power fade, and accelerated cylinder wear over a race season. Sized at 44.45mm for standard "A" bore cylinders, this Japanese-manufactured piston restores factory tolerances and peak horsepower output across the powerband.

Cast from a specialized high-silicon-content aluminum alloy, this piston exhibits minimal thermal expansion under heavy moto heat and is CNC-machined to precise tolerances. The piston skirt features a low-friction moly coating that reduces drag against the cylinder wall and prevents scuffing during break-in. Each package comes complete with the piston, premium ring set, wrist pin, and circlips to ensure a comprehensive top-end refresh.

Top Features: ProX Piston Kit

• Manufactured in Japan as a direct replacement component engineered for factory fitment.
• Cast from high-silicon-content aluminum alloy designed to resist thermal expansion and stress under race conditions.
• CNC-machined to extremely close dimensional tolerances for consistent ring seal and compression.
• Features a moly-coated piston skirt to reduce friction, minimize heat, and prevent cylinder scuffing.
• Complete rebuild kit includes the 44.45mm piston, ring set, wrist pin, and circlips.

Please review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.

Fitment List

Frequently Asked Questions

Q: What does the "Size A" designation mean for this piston kit?
A: "Size A" indicates a 44.45mm outer diameter engineered for standard-bore cylinders within factory "A" sizing tolerances, ensuring proper piston-to-cylinder wall clearance.

Q: Does this piston kit come with a wrist pin and circlips?
A: Yes, each kit includes the piston, piston ring set, wrist pin, and two circlips.

Q: What is the benefit of the moly skirt coating?
A: The moly coating reduces surface friction against the cylinder wall, assisting with safe break-in and protecting against skirt scuffing under high engine temperatures.

Expert Pro-Tip: Always measure your piston ring end-gap inside the cylinder bore using a feeler gauge before assembling the top end. Position the circlip gap at the 6 o'clock or 12 o'clock position (never over the pin bore notch), and thoroughly oil the small-end wrist pin needle bearing with two-stroke pre-mix oil before sliding the cylinder down over the piston.

Recommended Pairings:

• Kawasaki KX65 Performance Parts & Upgrades
• Kawasaki KX 2-Stroke Performance Parts
• Suzuki Mini Performance Parts

At Moto-House MX, we carry the best brands in motocross and off-road performance. Our team has over 40 years of experience helping riders get more out of their bikes. We pride ourselves on great customer service, and every item ships FAST - straight to your door.

Moto-House MX - Choice of Champions - Your premier powersports source with great customer service and lightning-fast shipping straight to your door.