Wacker Neuson 5100005808 Cylinder and Piston Complete

The Wacker Neuson Cylinder and Piston Complete is a genuine OEM assembly designed for BTS 630 and BTS 635S series gasoline cut-off saws. As a direct factory replacement, this assembly restores proper compression and engine output to saws that have suffered power loss, excessive blow-by, or scored cylinder walls. Verified against multiple BTS 630 and BTS 635S configurations, including standard cut-off and floor saw variants, part number ensures a correct, hassle-free installation with no guesswork on fitment.

Key Features

• Genuine OEM Compression Integrity — Factory-matched bore diameter and piston ring seating tolerances maintain the precise compression ratio the BTS engine needs for consistent starting and full cutting power.
• Complete Assembly — Supplied as a matched cylinder and piston complete unit, so the bore and piston are pre-sized to each other — no separate pairing or selective fitting required.
• Broad BTS Series Coverage — Fits BTS 630 and BTS 635S cut-off and floor saw variants, including 12-inch/20mm arbor configurations and multiple production runs across those model families.
• Restores Lost Engine Performance — A worn cylinder or piston causes hard starting, loss of blade speed under load, and increased fuel consumption; replacing the assembly brings engine output back to spec.
• Fuel System Safety Compliance — Correct cylinder sealing prevents unburned fuel from migrating past the rings into the crankcase, reducing the risk of crankcase pressure buildup and oil contamination in a fuel-system-critical two-stroke engine.

The cylinder and piston assembly forms the core of the two-stroke engine's combustion chamber. The cylinder bore contains the piston as it travels up and down, compressing the air-fuel mixture and transferring the force of combustion into rotational power at the crankshaft. Over time, the bore and piston rings wear due to heat, abrasive dust ingestion, and normal operating cycles — leading to compression loss, hard starting, and sluggish blade speed. Replacing the cylinder and piston complete unit restores the tight tolerances the engine depends on for reliable ignition and full power output under cut-off and floor saw loads.

Part Details

Compatibility & Fitment

Verify Before You Order

Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.

Why Buy From DHS Equipment

Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.

Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.