Yamaha R1 Charging System Rotor Magnet Failure

The 2004 onwards R1 and FZ1 model had issues with the charging system rotor magnets breaking off the epoxy and completely destroying the stator and sending metal particles all through the oil. It isn’t an “if” it’s a “when” it’ll happen as the epoxy gets brittle over heat cycles. They quietly replaced the poorly designed rotor with a new part in 2007 onwards. The new part is sold as a replacement for the 2005+ models when you go to order a replacement. Again, should have been a recall but Yamaha kept quiet about it. Read on to find out more…

If this issue has happened to you and you need to replace the magneto, here is a How To Guide

 

Yamaha R1 magneto
Yamaha R1 magneto 5VY-81450-00-00 poorly designed with individual magnets epoxied to the rotor.

The magento when exposed to high temperatures will eventually fail as the epoxy falls apart. When the failure occurs, there will be a “bang” and magnets will come off and attach themselves to the stator and also send small pieces throughout the engine.

 

magnets from the R1 magneto attached to the stator
magnets from the R1 magneto attached to the stator
magnets from the R1 magneto attached to the stator
magnets from the R1 magneto attached to the stator

If this failure occurs on your bike, ensure you stop riding it as soon as possible and remove the damaged parts. Run a magnet everywhere around the inside of the case to pick up any debris. It is also recommended that you remove the sump (which requires removal of the exhaust) and clean out the entire sump and pickup as debris can clog the sump pickup.

 

2SH-81450-00
Upgraded magneto generator from the 2007 onwards R1 Part # 2SH-81450-00-00

As you can see, the new magneto generator has a sleeve inside which prevents this failure from occurring. Yamaha did nothing to prevent this failure on the older bikes such as a recall. They quietly revised the part numbers for the older bikes to match the part used in the newer generation.

If this issue has happened to you and you need to replace the magneto, here is a How To Guide

2 thoughts on “Yamaha R1 Charging System Rotor Magnet Failure

  1. Do you happen to know if I can get just the magnet with whatever piece I need to attach it to the inside of the flywheel? I’d like to rebuild the rotor flywheel myself,

    1. Hi there are people who have made a new insert with magnets but it is really difficult an also very risky as you need to get the magnets oriented correctly, space them out correctly AND glue them with the correct epoxy to resist oil and high temperature cycles. The new design is far, far better due to the sleeve and will outlast the rest of the motor. I highly recommend you just buy the new replacement part rather than put new magnets in. Yamaha doesn’t sell individual magnets anyway.

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