The Honda 13101-812-000 Piston (Standard) is a genuine OEM component designed for E300, EM400, and ER400 generators. As an authentic Honda part, it is manufactured to the same specification as the original, ensuring a correct fit in the bore without the guesswork of an off-spec replacement. This standard-bore piston is the right choice when the cylinder has not been bored oversize — verify your engine's bore condition before ordering to confirm the Standard sizing applies to your unit.
Key Features
- Genuine OEM Piston — sourced directly from Honda, this piston matches the original dimensions for correct bore clearance, ring groove geometry, and wrist pin alignment critical to proper combustion sealing
- Standard Bore Sizing — the Standard designation means this piston is sized for an unmodified, factory-dimension cylinder bore; confirm your cylinder has not been bored oversize before fitting
- Generator Engine Fitment — designed for the E300, EM400, and ER400 generators; check the serial number on your unit against the fitment table to confirm this part applies to your specific production range
- Compression and Power Restoration — a worn or damaged piston allows combustion gases to bypass the rings, causing lost compression, hard starting, excessive oil consumption, and reduced generator output; this replacement restores the tight bore seal the engine depends on
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 transferring combustion force to the crankshaft via the connecting rod on the power stroke. The piston also works with its ring set to seal combustion gases above and control oil below. When a piston wears, cracks, or scores, compression drops sharply — the generator engine loses power, burns oil, and may refuse to start reliably. Replacing a failed piston with a correctly sized OEM unit restores the bore seal and brings combustion efficiency back to specification.
Part Details
| Part Number | 13101-812-000 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Piston (Standard) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Generator | E300, EM400, ER400 | All |
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.
