potential fz1 buyer - a good old rotor question

[Torqfazer]

Hi. did a search so im pretty certain this is a first for this question.


So say im going to buy a bike and in its past the magnets flew in the rotor and lets say it was apparently fixed.


first question is
re there any potential pitfalls here?


second
any obvious 'tells' that it happened at all?


cheers

[unfazed]

Find out who"fixed" it was it a Yamaha rotor or a pattern rotor and  was the sump dropped to check for the bits that escaped through the hole in the rotor area.

If it was a pattern spare was it from these guys, they are apparently great to deal with and a fraction of the Yamaha replacement cost
https://www.rmstator.com/documents/LandingPages/ImprovedFlywheelYamahaYZFR1/us-en.html?utm_source=rmstatorcom&utm_medium=insite-ad&utm_campaign=CPG2020Q04-YRF&utm_content=usa--en

[Torqfazer]

unfazed
Sorry its been a while. thanks for the response. cheers

[b1k3rdude]

Find out who"fixed" it was it a Yamaha rotor or a pattern rotor and  was the sump dropped to check for the bits that escaped through the hole in the rotor area.

Just add to this, I would request a receipt. You could also buy a spare gasket and remove the cover taking care to make sure the rotor stays in place and see if the superseded part has been installed. But not every owner is going to want to do that, so you could ask him/her if they don't mind you taking it to a garage for them to check it and you will pay for that etc.

And some info regarding the rotor, what seems to cause the rotor to fail is the poor adhesion of the magnet segments, once they start moving this crates imbalance, it's this imbalance that causes the rear bearing (93306-20230) behind the idler sprocket (5VY-15517-00) and the front bearing (93306-20124)to fail. The design of the rotor/magnet on the 2006/2007 is poor hence why Yamaha started selling the superseded/update version on the quiet with no announcement what so ever! When what they should have been doing, is issuing a recall on that fucking part and/or offering free swap for anyone who wanted it (as the job only takes a home mechanic 30-45mins to do, let alone a trained mechanic)
Here is a video of a well known motorcycle tuber doing said job -

http://www.youtube.com/embed/NoQ5ROywKto

[Gnasher]

I've replaced a handful of these, I've not had one that the rear bearing problem.  Some were changed because of charging issues and have obvious signs of magnets starting to dislodge others changed as precaution, I've not worked on one that self destructed, but I've seen one

The feedback I've had from talking to others in the know is they fail due to poor adhesion of the magnet segments, once they start moving this crates imbalance, it's this imbalance that causes the bearings to fail not the other way around.     

[b1k3rdude]

The feedback I've had from talking to others in the know is they fail due to poor adhesion of the magnet segments, once they start moving this crates imbalance, it's this imbalance that causes the bearings to fail not the other way around.

Thanks for the updated info, will correct my post above and add this to the FAQ!