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The Goodman B4089343 is a genuine OEM burner orifice (spud) drilled to a #43 bore for the DMS80904BNA 80% AFUE gas furnace and compatible Goodman/Amana models. The orifice threads into the manifold and meters the exact gas flow into each in-shot burner, setting the firing rate and BTU output. A worn, enlarged, or debris-clogged orifice throws off the air/fuel ratio, causing sooting, lifting flame, or under-firing.
OEM Goodman orifices are precision-drilled and gauged to the factory #43 spec, guaranteeing the rated BTU input and clean flame. Generic spuds can vary slightly in bore diameter — even a fraction off changes the firing rate and can create a safety hazard. For correct combustion, genuine OEM is essential. Match the orifice size to your gas type and altitude.
Moderate (3/5) — Shut off gas and power, unthread the old orifice from the manifold, and torque in the new spud with thread sealant rated for gas. About 30–45 minutes. Always leak-test with soap solution after. Gas work — use a licensed technician if unsure.
Compatible with Goodman and Amana furnaces using #43 natural-gas orifices. Contact info@nationalhvacparts.com to verify size for your setup.