DENSO W27ESR-Uequivalent & cross reference

The DENSO W27ESR-U spark plug is directly equivalent to NGK BR9ES and NGK BR9EIX, confirmed by shared applications in both manufacturers' official catalogues.

Equivalents

Part	Shared applications	Agreement
NGK BR9ES	13	87%
NGK BR9EIX	14	50%

Verified fitments for the DENSO W27ESR-U

Yamaha DT 125 R (1988–2003)
Yamaha TDR 250 (1988–1992)

Equivalence confirmed by 3 independent sources, last verified 22 July 2026. Always confirm fitment against your owner's manual.