The Honda 13102-ZF6-W01 Piston (0.25) is a genuine OEM oversized piston designed for GX390 horizontal shaft engines and a wide range of Honda EB, EM, and EU series generators. As an OEM component, this piston is produced to Honda's exact dimensions and tolerances, making it the correct choice for engine rebuilds requiring a 0.25 mm oversize bore. This part fits across a broad equipment range — including EB3800, EB4000, EB5000, EB6500, EB7000, EM3800, EM4000, EM5000, EM6500, EM7000, and EU6500 generators, as well as GX390 engines — so confirm the oversize designation matches your machined bore before ordering. Always cross-reference the serial number on your unit against the fitment table to ensure part number 13102-ZF6-W01 is correct for your specific build.
Key Features
- Oversize Bore Fit — the 0.25 designation identifies this as an oversized piston for engines with a 0.25 mm overbore; match this specification to your cylinder machining before purchasing.
- Genuine OEM Construction — manufactured by Honda to the same dimensional specifications as the original piston, ensuring correct ring groove geometry, pin bore sizing, and skirt clearance for proper sealing and oil control.
- Broad Fitment — covers GX390 horizontal shaft engines and Honda EB, EM, and EU series generators including the EB5000, EM5000, EM7000, EU6500, and others; verify your model and serial number against the fitment table.
- Serial Number Verification Recommended — Honda supersedes piston part numbers at production breaks, so check your machine's serial number against the compatibility data to confirm this is the correct oversize piston for your engine.
The piston is the reciprocating heart of the combustion cycle, traveling up and down inside the cylinder bore to compress the air-fuel mixture and transfer the force of combustion to the crankshaft via the connecting rod. In a worn or damaged engine, the original bore is often machined slightly oversize to restore a true, round surface — and an oversize piston like this 0.25 unit is fitted to maintain the correct running clearance that the rings need to seal combustion gases and control oil consumption. When piston-to-bore clearance is off — whether from a worn standard piston or an incorrectly sized oversize replacement — the engine will suffer from blow-by, increased oil consumption, loss of compression, and hard starting.
Part Details
| Part Number | 13102-ZF6-W01 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Piston (0.25) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Generator | EB3800, EB4000, EB5000, EB6500, EM3800, EM4000, EM5000, EM6500 | 4278970-9999999 |
| Horizontal Shaft Engine | GX390 | All |
| Inverter Generator | EB7000, EM7000, EU6500 | 4278970-9999999 |
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.
