The Honda 91353-921-310 O-Ring (5.5MM) is a genuine OEM sealing component designed for B75, BF100, BF5, BF50, BF75, and BF8 portable and outboard motors. As a direct Honda OEM part, it is manufactured to the exact dimensions and material grade Honda specifies for these applications. Confirm your motor's model against the fitment table before ordering, as Honda updates part supersessions at serial breaks and the correct O-ring size is critical to a leak-free seal.
Key Features
- OEM Sealing Integrity — manufactured to Honda's exact 5.5MM specification, ensuring the dimensional accuracy that a correct compression seal depends on in a marine environment
- Direct OEM Replacement — sourced directly from Honda, this O-Ring installs as a drop-in replacement with no modification needed to the mating surfaces
- Broad Outboard Fitment — listed for B75, BF100, BF5, BF50, BF75, and BF8 Honda portable and outboard motors; verify your serial number against the fitment table to confirm the correct application
- Leak Prevention — a degraded or incorrectly sized O-ring allows fluid or pressure to bypass the seal, leading to performance loss or internal damage; replacing it promptly with the correct part keeps the motor running as intended
An O-ring is a circular sealing element seated in a machined groove between two mating components. When the joint is assembled and torqued, the O-ring compresses to fill the gap, blocking the passage of fluid or pressure between the two surfaces. In a marine outboard motor, O-rings are used throughout the cooling, fuel, and lubrication circuits where a reliable, low-profile seal is required. When an O-ring ages, hardens, or is damaged during service, it loses its ability to conform to the groove and the seal fails — resulting in leaks that can affect cooling flow, fuel delivery, or oil retention depending on where the ring is located.
Part Details
| Part Number | 91353-921-310 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | O-Ring (5.5MM) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Outboard Motor | BF50, BF75 | All |
| Portable Outboard Motor | B75, BF5, BF8, BF100 | 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.
