front sprocket nut

[chrischristopherson1313]

Nut on the front sprocket it's loose. I can screw it with my fingers (not even using power)
Is it normal or it should be tight.
The screw it's still on the shaft hold by washer

[Fazerider]

It should be tight, but it is a common problem.
http://foc-u.co.uk/index.php?topic=92.0

[chrischristopherson1313]

Ok luckily the nuts didnt come of yet
I have ordered bigger nut from yamaha.
Do you think it's safe to run a bije for those couple of days until new nut come?

[Fazerider]

No, it's really not to be recommended.
Having said that, the early Fazers have a plate screwed to the inside of the sprocket cover which prevents a loose nut from actually falling off the end of the shaft and a lot of us have probably ridden quite a long way with it in that condition without realising.

[His Dudeness]

What condition are the threads in?

[chrischristopherson1313]

Was trying unscrew with fingers only. Although it's loose doesn't come of so proboly thread it's damaged a little. Will wait for new nut first and then will try to unscrew it.

[darrsi]

Can i just ask what the exact year of your bike is please on behalf of someone elses curiosity?

[chrischristopherson1313]

1988

[tommyardin]

These front sprocket nuts are a real problem it seems. As I mentioned in another post on here my 2003 FZS600 foxeye still has the original 9mm nut fitted, I have the upgrade kit 12mm nut and washer on the bench in my shed ready to go, but, try as I may I cannot undo the one that's on the bike.
I have straightened out the lock/tab washer 32mm socket with 500mm bar and put all the pressure I can on it, had a mate sit on bike, in gear, brakes on and fucking near burst a blood vessel trying to loosen that bastard to no avail. One of the other foccers in here came up with the solution which I have yet to do, that is ride down to a friendly mechanic pop the sprocket cover off the bike and get him to put his air/impact wrench on it, nip it back up tight by hand ride home and complete the task. I thought KingKong was an American but the cupid stunt worked for Yamaha in the front sprocket nut department when they built my bike.


But what a great bike they are though, great for pottering about in town and great for tear arseing about down country lanes, basically a brilliant all rounder with a nod towards the retro look, I love it.

[tommyardin]

The fact that Chris's nut rotates but does not actually come off does not bode well, if it was the threads in the nut that were gone the nut would come off easily, because the orifice in the nut would be larger. It points to the threads on the shaft being stripped  I really hope for his sake that is not the case as I understand it is a complete strip down to replace the shaft.
Although one member in here tack welded the nut on his shagged shaft and has ridden the bike for a number of years like that. (Not ideal though, but a solution as a cheap but practicle workaround)


Good luck Chris keep up posted as to how it pans out 

[darrsi]

1988

Okay, i'll meet you half way and we'll call it a 1998.

FAZERSHARP, are you reading this?   

[chrischristopherson1313]

 would be almost my age:)
Yep it's 98 typed it wrongly

[fazersharp]

1988

Okay, i'll meet you half way and we'll call it a 1998.

FAZERSHARP, are you reading this?   

Im here ---- before we go to deathcon 5
Chrischristopherson could you tell us (me) how many miles your bike has done

[darrsi]

1988

Okay, i'll meet you half way and we'll call it a 1998.

FAZERSHARP, are you reading this?   

Im here ---- before we go to deathcon 5
Chrischristopherson could you tell us (me) how many miles your bike has done

What's that gotta do with the price of fish? 

[fazersharp]

1988

Okay, i'll meet you half way and we'll call it a 1998.

FAZERSHARP, are you reading this?   

Im here ---- before we go to deathcon 5
Chrischristopherson could you tell us (me) how many miles your bike has done

What's that gotta do with the price of fish? 

Ok I am waiting for him to say 24k or more in which case the nut will of been off to already replace the sprocket---- meaning it is not a factory fitted un touched nut that has came loose, and therefore still maintaining my pet theory.

So chris do you actually know if it has had a new chain and sprocket set in the past

[chrischristopherson1313]

28k but the nut it's still there just loose a bit.
It's original nut and sprocket looks as it was changed

[chrischristopherson1313]

Will wait for new nut and then see
I am optimistic

[fazersharp]

28k but the nut it's still there just loose a bit.
It's original nut and sprocket looks as it was changed

Ok thank you for the info

Just as I thought 28k and already been replaced

DARRSI. are you reading this?  (I believe it goes  )

[fazersharp]

chris
for some background info on this banter see here http://foc-u.co.uk/index.php/topic,19504.msg225613.html#msg225613

[darrsi]

28k but the nut it's still there just loose a bit.
It's original nut and sprocket looks as it was changed

Ok thank you for the info

Just as I thought 28k and already been replaced

DARRSI. are you reading this?  (I believe it goes  )

The sprocket may have been replaced, but still the original nut!
Hardly surprising it's done over 24K on an 18 year old bike!

[Fazerider]

Here's some competition for the later-bikes-have-an-undersized-shaft theory:
a) the nut was underspecified
b) early Fazers had it glued on with a ridiculously strong threadlock (hence the need for a scaffolding pole extension on the socket to shift it )
c) Yamaha realised they'd made the bond too strong and switched to a different compound on later Fazers which proved to be inadequate
d) when owners/mechanics replaced the sprocket, the thread was contaminated with oil and they didn't use high-strength superglue hence subsequent failures on early bikes
e) Yamaha's instruction to dealers regarding shaft replacement relied on a measurement of the diameter of the threaded portion not because they'd made some too small, but as a means of determining whether the thread had been too badly damaged by the loose nut and/or sprocket.

[fazersharp]

28k but the nut it's still there just loose a bit.
It's original nut and sprocket looks as it was changed

Ok thank you for the info

Just as I thought 28k and already been replaced

DARRSI. are you reading this?  (I believe it goes  )

The sprocket may have been replaced, but still the original nut!
Hardly surprising it's done over 24K on an 18 year old bike!

You still don't get it do you - its not the nut its the output shaft on 99 onwards.
We are yet to find a 98 with an un touched nut that has had the nut come off on its own

[fazersharp]

Here's some competition for the later-bikes-have-an-undersized-shaft theory:
a) the nut was underspecified
b) early Fazers had it glued on with a ridiculously strong threadlock (hence the need for a scaffolding pole extension on the socket to shift it )
c) Yamaha realised they'd made the bond too strong and switched to a different compound on later Fazers which proved to be inadequate
d) when owners/mechanics replaced the sprocket, the thread was contaminated with oil and they didn't use high-strength superglue hence subsequent failures on early bikes
e) Yamaha's instruction to dealers regarding shaft replacement relied on a measurement of the diameter of the threaded portion not because they'd made some too small, but as a means of determining whether the thread had been too badly damaged by the loose nut and/or sprocket.

Also my pet theory is that the original 98s shaft was only produced in 1 factory and it was after 98 when production stepped up that other factory's were brought online to produce the shafts which were undersize. So all 98s are ok and thereafter its a game of chance where your shaft was made as to whether or not you have the issue because remember that not all 99 onwards have the issue. And ones yam found out they made sure the shaft spec on new bikes was correct

[tommyardin]

Now it seems we have a conflict of interest here (Or am I being thick, answers on the back of a sealed white envelope to P O Box 999 Basingstoke)were some of the shafts manufactured undersize or iare some undersize because of a loose nut chattering and wearing the apex off the top of the shaft threads.


I was born in 1947 and my Mrs reckons my shaft is undersized, and my nuts chatter as well. [size=78%]  [/size]

[chrischristopherson1313]

28k but the nut it's still there just loose a bit.
It's original nut and sprocket looks as it was changed

Ok thank you for the info

Just as I thought 28k and already been replaced

DARRSI. are you reading this?  (I believe it goes  )

The sprocket may have been replaced, but still the original nut!
Hardly surprising it's done over 24K on an 18 year old bike!

IT'S definetelly old small nut (really rusty) but I can't be sure if it's original

28k but the nut it's still there just loose a bit.
It's original nut and sprocket looks as it was changed

Ok thank you for the info

Just as I thought 28k and already been replaced

DARRSI. are you reading this?  (I believe it goes  )

The sprocket may have been replaced, but still the original nut!
Hardly surprising it's done over 24K on an 18 year old bike!