The Honda 13012-Z5F-004 Piston Ring Set (0.50) is a genuine OEM oversized piston ring set designed for Honda GX240 horizontal shaft engines, EB, EG, and EM generators, WT20 and WT30 water pumps, and FRC800 tillers. As a direct Honda OEM component, this ring set is manufactured to the same specifications as the original rings installed at the factory, ensuring the correct ring gap, groove fit, and profile for the 0.50 mm oversize bore. Confirm fitment by checking your unit's serial number against the compatibility table, as Honda supersedes parts at specific serial breaks across this wide range of equipment.
Key Features
- Oversize Bore Fitment — the 0.50 mm oversize designation means this ring set is sized for a cylinder that has been bored 0.50 mm over standard; verify your bore size before ordering to ensure the correct ring-to-wall clearance
- Genuine OEM Ring Geometry — Honda-sourced rings deliver the correct compression ring profile and oil control ring tension for this engine family, maintaining proper cylinder sealing after a rebore
- Broad Equipment Coverage — fits GX240 horizontal shaft engines along with Honda EB3500, EB3800, EB4000, EB5000, EB6500, EG3500, EM3500, EM3800, EM4000, EM5000, and EM6500 generators, WT20 and WT30 water pumps, and the FRC800 tiller
- Serial Number Verification Recommended — Honda updates parts at defined serial breaks; check your machine's serial number against the fitment table to confirm this ring set applies to your specific unit
- Compression and Oil Control Restored — worn or broken piston rings allow combustion gases to blow past the piston and oil to enter the combustion chamber; a correctly fitted ring set restores compression, reduces oil consumption, and returns the engine to full power output
Piston rings form the dynamic seal between the piston and the cylinder wall. The compression rings trap combustion pressure above the piston to drive the power stroke, while the oil control ring scrapes excess oil back down the cylinder bore to prevent it from burning in the combustion chamber. When rings wear, lose tension, or break, an engine loses compression, burns oil, produces visible smoke, and delivers noticeably reduced power. Replacing the ring set during a rebore or overhaul restores that seal, bringing the engine back to the output and efficiency it had when new.
Part Details
| Part Number | 13012-Z5F-004 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Piston Ring Set (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.
