The alternator rotor on the Yamaha FZ-1, Yamaha FZ-8 and Yamaha YZF-R1 RN19 can suffer a broken inner retaining cage that holds the magnets in position, causing the engine to lock or the alternator to stop generating power. The magnets come loose and then rub directly against the alternator coils. If you notice a drop in alternator voltage, check the alternator or rotor to ensure the magnets are still completely secure. Otherwise, always replace it to prevent further damage. If the rotor has already failed, the entire engine does not necessarily have to be dismantled, but it is advisable to remove the sump and clean the engine from below, carefully removing all swarf or broken pieces. For the repair, please therefore order the sump gasket (4C8134140000), alternator cover gasket (2D1154511000), and preferably a magnetic sump plug (OAS1415) and a new oil filter (5GH134408000) as well, so that remaining magnet fragments can also be caught. Installing our new genuine Yamaha rotor normally restores system voltage to around 14 volts.
Alternative item number: 5VY-81450-00-00
Related links to "Alternator rotor FZ-1, FZ-8, R1-RN12–19, 2SH814500000 ROTOR ASSY, genuine Yamaha spare part"
