The Honda 13103-ZE2-W01 Piston (0.50) is a genuine OEM oversized piston designed for a wide range of Honda GX240 horizontal shaft engines, EB, EG, and EM generators, WT20 and WT30 water pumps, and the FRC800 tiller. As an OEM component, this piston is produced to Honda's exact dimensional tolerances, ensuring the bore clearance, ring groove geometry, and pin bore alignment match what Honda engineered for this engine family. The (0.50) designation identifies this as a 0.50 mm oversized piston, intended for engines whose cylinders have been bored out to accept an oversize replacement — confirm your cylinder bore measurement before ordering.
Key Features
- Oversize Variant — Match Before You Order — the (0.50) designation means this piston is sized for a cylinder bored 0.50 mm over standard; it will not seat correctly in a standard-bore or differently oversized cylinder. Measure your bore first.
- OEM Dimensional Accuracy — genuine Honda manufacture means ring grooves, pin bore diameter, and skirt profile are held to the same tolerances as the original, supporting proper compression sealing and oil control once the rings are fitted.
- Broad Fitment Across Honda Equipment — fits GX240 horizontal shaft engines, EB3500, EB3800, EB4000, EB5000, EB6500, EG3500, EM3500, EM3800, EM4000, EM5000, EM6500 generators, WT20 and WT30 water pumps, and the FRC800 tiller, all of which share this engine family.
- Serial Number Check Recommended — Honda supersedes parts at production serial breaks; always verify your unit's serial number against the fitment table to confirm part number 13103-ZE2-W01 is correct for your specific machine before installation.
- Compression Restoration — a correctly sized piston with a properly bored cylinder restores compression to spec, directly recovering the power output and starting performance lost to a worn bore.
The piston is the reciprocating heart of a four-stroke engine. It travels up and down inside the cylinder bore, compressing the air-fuel mixture on the upstroke and transmitting the force of combustion to the crankshaft via the connecting rod on the power stroke. When a piston wears, its skirt develops excessive clearance against the bore, compression drops, oil consumption rises, and the engine loses power, runs roughly, or becomes difficult to start. An oversized piston like this one is used after the cylinder has been professionally bored to remove wear — the new piston fills the enlarged bore correctly, restoring the tight clearance that sealing and performance depend on.
Part Details
| Part Number | 13103-ZE2-W01 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Piston (0.50) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Generator | EB3500, EB3800, EB4000, EB5000, EB6500, EG3500, EM3500, EM3800, EM4000, EM5000, EM6500 | 4869815-9999999 |
| Horizontal Shaft Engine | GX240 | All |
| Tiller | FRC800 | 4869815-9999999 |
| Water Pump | WT20, WT30 | 4869815-9999999 |
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.
