This genuine Honda radiator cap seals the cooling system and helps maintain proper pressure in the radiator on compatible Honda motorcycles and ATVs. It is a small part, but a weak, damaged, or incorrect radiator cap can cause coolant loss, overheating symptoms, or poor cooling-system pressure control.
Use this OEM Honda radiator cap when the fiche calls for Honda part number 19045-MZ1-621 or one of the verified superseded numbers. It is commonly searched as a radiator cap, coolant cap, cooling system cap, or radiator pressure cap.
Key Features
• Genuine Honda OEM part
• Honda OEM part number: 19045-MZ1-621
• Honda part description: Cap, Radiator / Cap Comp., Radiator
• Supersedes / replaces: 19045-GBF-700, 19045-GBF-770, 19037-KA4-701, 19037-KV3-003, 19111-MM9-000, 19037-KA4-700
• Sold individually
• Quantity required: typically 1 per radiator assembly
• Buyer note: confirm the OEM number, radiator neck style, cap pressure requirement, and cooling-system diagram before ordering.
Fitment / Compatibility
• Honda CB400F CB-1 (1989-1990)
• CBR1000F Hurricane (1987-1991, 1996)
• CBR1100XX Super Blackbird (1997-1998)
• CBR600F Hurricane (1987-1990)
• CBR600F2 (1991-1992)
• CBR600F3 (1997-1998)
• CBR600F4 (1999-2000)
• CBR600F4i (2001-2004)
• CBR900RR (1993-1999)
• CBR929RR (2000-2001)
• CR125R (1982-2007)
• CR250R (1982-2007)
• CR500R (1985-2001)
• CR80R (1983-2002)
• CR80RB Expert (1996-2002)
• CR85R (2004-2007)
• CR85RB Expert (2003-2007)
• CRF450R (2002-2003)
• GL1800 Gold Wing (2001-2004)
• GL1800A Gold Wing ABS (2001-2004)
• FSC600D Silver Wing (2002)
• XL600V Transalp (1989-1990)
• VFR700F2 Interceptor (1987)
• VFR750F Interceptor (1990-1992, 1997)
• VFR750R RC30 (1990)
• VFR800 Interceptor (1998-2001)
• RVT1000R RC51 (2000-2001)
• VT1100C Shadow Spirit (2001-2004)
• VT1100C2 Shadow Sabre (2000-2004)
• VT1100C3 Shadow Aero (2001-2002)
• VT600C Shadow VLX (1999-2003)
• VT600CD Shadow VLX Deluxe (1998-2003)
• VT750CA Shadow ACE (1998-1999)
• VT750CD Shadow ACE Deluxe (1998-2003)
• VTR1000F Super Hawk (1998-2002)
• VTX1800C (2002-2004)
• VTX1800N (2004)
• VTX1800R (2002-2004)
• VTX1800S (2002-2004)
• ATC250R (1985-1986)
• TRX250R FourTrax (1986-1989)
