Home
Ren's Biking Blog
Yamaha's Stripped Loose and Lost Sprocket Retaining Nuts
Blog Date - 03 August 2011
The Yamaha Fazer is a great bike, but it is not perfect. One problem Yamaha's had with quite a few bikes in their range is that of lost or loose front sprocket nuts. A search of the unofficial Fazer Owners Club website takes us to a whole list of owners who have lost their nuts... Perhaps I could have worded that better. Also looking around some other Yamaha owner's pages suggests that the Thundercat and R6 are known to suffer. The problem is that the large nut that holds the sprocket on is not up to the job, it's not tough enough.
The nut is held in place with a tab washer that is bent over the nut, to stop the nut unscrewing. Quite often the tab washer is still in place and the bent parts remain bent whilst the nut is missing or completely loose. This must imply the nut has not come undone, but has slipped over it's own thread. This is not a good state of affairs and I personally believe a recall should have been issued. What Yamaha have done is mentioned to a few of their dealers that if there's a problem then they may...or may not fix it. It's far too long a story to cover properly here.
My Fazer's been fine...so far. At 26,500 miles I've checked the sprocket nut and found all to be quite as it should be. Some owners have reported their machine also being fine up to 30, 40 and even 50,000 miles before the issue arose so I'm not out of the woods by any means. What Yamaha have done is "beefed up" the sprocket retaining nut. I have purchased a beefed up nut for the princely sum of £9 and when the chain is due for replacement, in probably another 5,000 miles, I shall fit the new sprocket with the new beefier nut.
If you wish to find out if you already have the beefy nut or the wimpy one...the beefy one is 12mm thick, the wimpy one is 9mm thick.
You will need part number 90891-10124, about £9 from you local Yamaha Stealer
When you see that only 2/3rds of the BIGGER nut has threads, just how few tiny threads are on the smaller 9mm item? Even the 12mm item looks a bit weedy.
Reader's Comments
Michael said :-
good information, thank you. sadly that problem is not limited to some models or manufacturer. When sprocket nut loose and shaft pitch flat it needs a new transmission shaft.
Or a special sprocket nut. Low cost and reliable.
http://sprocketnut.de.tl/
01/01/2000 00:00:00 UTC
Ren - The Ed said :-
I don't like people advertising by posting on my site....but...I think this may be useful for anyone facing a stripped sprocket nut. I'd welcome feedback from anyone who's user this product
01/01/2000 00:00:00 UTC
Name
Comment
Add a RELEVANT link (not required)
Upload an image (not required) -
Uploading...
Home
Ren's Biking Blog