Gear Oil Drain & Level Plug O-Ring Gasket Set for Honda Outboards

Premium-quality aftermarket gear oil drain plug and oil level/check plug O-ring seals for selected Honda 4-stroke outboard engines.

These small seals are fitted to the gearbox oil drain / level plugs and should be inspected when changing the lower-unit gear oil.

Designed as replacements for Honda part number 91301-ZW4-003.

Honda identifies this part as an O-Ring, 6.9 × 1.45 mm, and Honda gearcase diagrams show it fitted to the gearbox oil plug locations.

Fits Selected Honda Outboards

Suitable for a wide range of Honda 4-stroke outboards, including selected:

8 HP
10 HP
15 HP
20 HP
25 HP
30 HP
40 HP
50 HP
60 HP
75 HP
80 HP
90 HP
100 HP
115 HP
130 HP
135 HP
150 HP
175 HP
200 HP
225 HP
250 HP

Parts references list 91301-ZW4-003 across Honda 8–250 HP 4-stroke applications, with many applications from 2004 onwards.

Examples of Compatible Model Families

BF8, BF10, BF15, BF20, BF25, BF30, BF40, BF50, BF60, BFP60, BF75, BF80, BF90, BF100, BF115, BF130, BF135, BF150, BF175, BF200, BF225 & BF250

Replaces Honda Part Number

91301-ZW4-003
91301ZW4003
HZW491301003

O-Ring Size

6.9 × 1.45 mm

OEM part numbers are used for identification and reference purposes only.

Product Features

Gear oil drain plug O-ring / gasket
Gear oil level / check plug seal
For selected Honda outboard engines
8 HP–250 HP
4-stroke applications
Size: 6.9 × 1.45 mm
Ideal for routine gearbox oil servicing
Helps provide the correct seal around the gear oil plugs
Marine-grade quality aftermarket part
Manufactured to OEM specifications
Direct replacement for the corresponding OEM application
New replacement parts

Important – Recommended During Gear Oil Changes

The gear oil drain and level plug seals are inexpensive service items but are important for maintaining a proper seal in the lower unit.

Honda parts diagrams show applications where two 91301-ZW4-003 O-rings are used in the gearcase, making them suitable for replacing the seals during a gearbox oil change.

Important – Please Check Compatibility

Please do not order by horsepower or appearance alone.

Honda has used different gearbox arrangements across its outboard range.

Before purchasing, please check:

Exact engine model
Engine year
Gearcase arrangement
Existing drain plug seal
Original Honda part number

For the safest identification, check that your engine requires:

91301-ZW4-003

If the part looks the same as yours, this does not always mean it is the correct one for your outboard.

If you are unsure, please send us your engine model and serial number before purchasing and our technical team will be happy to check compatibility.

Why Buy From SSI Marine?

Marine-grade aftermarket & OEM-spec parts
Workshop-tested products
More than 10 years supplying outboard parts
UK stock
Same working day dispatch before 1 PM Monday–Friday
Royal Mail Tracked 24
Technical support from experienced outboard specialists
Collection available from Leigh, Greater Manchester

Honda Outboard 8 HP-250 HP Gear Oil Drain Plug O-Ring Gasket Set 91301-ZW4-003