The Honda 13104-ZF6-W01 Piston (0.75) is a genuine OEM oversize piston designed for GX390 horizontal shaft engines and a broad range of Honda generators, including the EB3800, EB4000, EB5000, EB6500, EB7000, EM3800, EM4000, EM5000, EM6500, EM7000, EU6500, and associated equipment. The (0.75) designation identifies this as a 0.75 mm oversize piston intended for use in bores that have been machined or honed to the matching oversize — confirm your engine has been resized to this dimension before ordering. As a genuine Honda OEM component, this piston is manufactured to the same standards as the original, ensuring correct bore clearances, ring groove dimensions, and wrist pin fit for the engine family it serves.
Key Features
- Oversize Variant — Verify Before You Order — the (0.75) designation means this piston is sized for a bore that has already been machined 0.75 mm over standard; it is not a drop-in for a standard-bore engine. Match this size to your machined bore before purchasing.
- Genuine OEM Construction — manufactured by Honda to original equipment tolerances, with correct ring groove profiles and wrist pin bore geometry for proper ring seating and piston-to-rod fit in the GX390 engine family.
- Broad Generator and Engine Fitment — covers GX390 horizontal shaft engines as well as EB, EM, and EU generator models including the EB3800, EB5000, EB6500, EM5000, EM7000, EU6500, and more; check the fitment table and your unit's serial number to confirm this is the correct oversize for your machine.
- Restored Compression and Power Output — a correctly fitted oversize piston restores proper bore seal after cylinder wear, recovering compression pressure and fuel efficiency that a worn standard-size piston can no longer maintain.
The piston is the reciprocating component inside the engine cylinder that converts combustion pressure into crankshaft rotation. It must fit the bore to a precise clearance: too loose and combustion gases blow past the rings, robbing the engine of compression and fouling the oil; too tight and the piston seizes. An oversize piston like this one is used after the cylinder bore has been measured, found worn beyond standard limits, and machined or honed to an oversize dimension — in this case 0.75 mm over the original bore diameter. Installing the correct oversize piston with matched rings restores the cylinder's compression seal, allowing the engine to deliver its rated power output and run cleanly.
Part Details
| Part Number | 13104-ZF6-W01 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Piston (0.75) |
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.
