Vertex Top End Piston Kit (48.450mm / B-Size) VTK23637B-1 — Kawasaki KX85 2014-2025

Vertex Top End Piston Kit (48.450mm / B-Size) VTK23637B-1 — Kawasaki KX85 2014-2025

Product Description

Give your youth racer's mini machine a complete top end refresh with the Vertex Top End Piston Kit. Engineered specifically for the Kawasaki KX85 platform, this setup provides everything required to restore factory compression and establish optimal internal cylinder efficiency. It is designed for competitive racers and off-road riders who demand reliable track performance and sharp throttle response from their 2-stroke engines.

Vertex manufactures these replicas using a specialized gravity cast aluminum alloy infused with an 18% silicone content. This metallurgical composition creates an exceptionally lightweight structure that reduces reciprocating mass while maintaining robust structural integrity under severe thermal stress. Furthermore, the piston skirts feature a high-tech Molybdenum Disulfide coating that accelerates the initial break-in period, minimizes friction levels, and extends the operational lifespan of the assembly.

Top Features: Vertex Top End Piston Kit

• Gravity cast aluminum alloy construction with an 18% silicone compound for reduced internal mass and robust structure.
• Piston skirts are treated with a Molybdenum Disulfide (MoS2) coating to decrease friction and accelerate initial track break-in times.
• Factory-supplied replica dimensions ensure exact tolerances and matching factory configuration for an precise renewal.
• Includes factory-spec replacement rings, wrist pin, circlips, top end gaskets, and the wrist pin bearing for a total overhaul.

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

Fitment List

Year Range	Vehicle Brand	Vehicle Model & Sub-Model
2014-2025	Kawasaki	KX85

Frequently Asked Questions

Q: What does the "B" size signify for this Vertex piston kit?
A: A "B" sized piston features a microscopic size adjustment (48.450mm diameter) over the stock "A" size to compensate for normal cylinder wear, successfully restoring factory compression thresholds without needing a complete cylinder re-bore.

Q: Are the replacement rings included in this kit up to factory standard?
A: Yes. All piston rings provided in this package are direct OEM replacements designed to establish a solid seal against the cylinder wall.

Expert Pro-Tip:

When installing a new top end on a high-revving 2-stroke like the KX85, always measure your cylinder bore with a dial bore gauge to verify it is within spec for a B-size piston. Before final assembly, check your piston ring end gap inside the cylinder bore using a feeler gauge. Proper ring gap prevents the ends from expanding and touching under extreme heat, which can cause catastrophic failures. Also, verify that the ring gaps are perfectly aligned with the locating pins on the piston so they do not catch on the cylinder ports during operation.

Recommended Pairings:
o Kawasaki KX85 Performance Parts & Upgrades
o Kawasaki Performance Parts

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