For cylinder work on a 1980 CB650, distinguish the head joint, base joint and cylinder-sleeve O-rings before ordering. Individual cover gaskets serve more limited repairs. Identify the exact engine and the parts being removed so similar gasket names do not confuse the order.
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Replace your cylinder sleeve O-rings with this Cylinder Sleeve O-Ring Set of 4, replacing OEM #91304-286-000.Key Features• Cylinder sleeve O-rings, 4 per set• Replaces...
Replace your CB650 cylinder head gasket with this Cylinder Head Gasket, replacing OEM #12251-426-306.Key Features• Cylinder head gasket• Replaces OEM #12251-426-306Fitment / Compatibility• All...
Rebuild your CB650 engine with this Athena Overhaul Engine Gasket Set. Athena of Italy is an original-equipment supplier to Yamaha, Honda, Kawasaki, Suzuki, and...
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Replace your CB650 or CB500/CB550 cylinder base gasket with this Cylinder Base Gasket, replacing OEM #12191-426-306.Key Features• Cylinder base gasket• Replaces OEM #12191-426-306Fitment /...
Choose sealing parts for the joints being disturbed
Head and base gaskets are separate items. The sleeve O-ring set supplies four pieces, while a cover gasket addresses its own perimeter. Match all of them to the actual repair scope.
The head gasket replaces 12251-426-306 and the base gasket replaces 12191-426-306. The four sleeve O-rings have reference 91304-286-000. Check the service procedure and the joints being separated before deciding which of these items the repair requires.
Use individual covers for a smaller repair
The linked valve-cover and alternator-cover gaskets provide focused options for their respective covers. Do not select a broad kit merely because oil is visible elsewhere on the engine; locate the source and inspect mating parts before purchasing.
Ordering questions
Does a head gasket include the base gasket?
They are separate products with different sealing locations and references. Order the parts for the actual strip-down rather than treating a cylinder gasket as a complete top-end package.
Do cylinder-sleeve O-rings replace the cylinder-base gasket?
No. The O-rings seal around the lower cylinder sleeves where the block enters the crankcase; the base gasket seals the block-to-crankcase joint. The sleeve set contains four O-rings for this four-cylinder engine. Match both types to the joints involved in the repair.
Can a cover leak be repaired with an individual gasket?
An individual gasket is available for each linked cover. First confirm the leaking joint and condition of its mating surfaces; a gasket listing does not diagnose the cause of the leak.
Not sure which part you need?
Send your model and year, plus photos of your existing part and any changes to the original setup.