Sierra 18-0549 Plug Off Cap, 1 Inch I.D., Replaces OMC 909829, V-8 Stern Drives and Inboards 1977 to Present

The Sierra 18-0549 Plug Off Cap is a machined marine plug designed to seal a 1 inch inside-diameter opening on qualifying V-8 model stern drives and inboards built from 1977 to present. It is a direct replacement for OMC part number 909829, making it a straightforward swap when the original plug is damaged, corroded, or missing during service and inspection work. The cap is a simple, single-piece component with no moving parts, built to hold a reliable seal against water and fluid intrusion at its mounting location. Its compact size and light weight of 0.05 pounds make it an easy, low-cost item to keep on hand as a spare for routine maintenance. Buyers working on qualifying V-8 stern drive and inboard applications should confirm the 1 inch I.D. Opening size before ordering, since Sierra also offers the 18-0550 Plug Off Cap with a larger 1 1/4 inch I.D. For the same application range but a different opening size. The 18-0549 carries UPC 030999874535 for easy identification when ordering or verifying stock.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-0549
• Inside Diameter: 1 inch
• Product Dimensions: 4 x 1 x 5 inches
• Weight: 0.05 pounds
• UPC: 030999874535
• Fitment: V-8 Model Stern Drives and Inboards (1977 to present)
• Replaces: OMC 909829

Fitment

• V-8 Model Stern Drives and Inboards (1977 to present)

Replaces (OEM)

• OMC 909829

Frequently Asked Questions

What is the Sierra 18-0549 Plug Off Cap? It is a machined plug off cap made by Sierra, part number 18-0549, used to seal a 1 inch inside-diameter opening on qualifying V-8 model stern drives and inboards.

What is the inside diameter of the 18-0549 plug off cap? The 18-0549 has a 1 inch inside diameter (I.D.).

What engines and drives does the Sierra 18-0549 fit? This cap fits V-8 model stern drives and inboards built from 1977 to present.

Does the Sierra 18-0549 replace OMC part number 909829? Yes, the 18-0549 is a direct replacement for OMC 909829.

What is the difference between the Sierra 18-0549 and Sierra 18-0550? The 18-0549 has a 1 inch I.D. And replaces OMC 909829, while the 18-0550 has a larger 1 1/4 inch I.D. And replaces OMC 909830; both cover V-8 model stern drives and inboards from 1977 to present but are separate part numbers, so the correct one depends on the opening size on your unit.

How much does the Sierra 18-0549 plug off cap weigh? It weighs 0.05 pounds.

Is the Sierra 18-0549 a genuine Sierra part? Yes, the 18-0549 is manufactured under the Sierra brand and is not discontinued.

What is the UPC for the Sierra 18-0549 plug off cap? The UPC for this Sierra plug off cap is 030999874535.

Will the Sierra 18-0549 fit a 1 1/4 inch opening? No, the 18-0549 is sized for a 1 inch I.D. Opening; a 1 1/4 inch opening requires the Sierra 18-0550 instead.

What years of V-8 stern drives and inboards does the 18-0549 cover? The 18-0549 plug off cap covers V-8 model stern drives and inboards from 1977 to present.