The bearing behind the front sprocket might be busted?

MrMogensen

... That's me!
Wanted to adjust the chain a tiny bit and I noticed something terrible.
When in NEUTRAL (engine off) and just turning the rearwheel by hand there is a significant click click click sound. At first I thought it was the read wheel bearings but the click's seems to originate from the front sprocket. I am not talking about chain-chatter. If I put my finger on the centre of the sprocket and turn the rear wheel I am almost certain I can feel tiny movements that matches the clicks.

Browsed through the factory service manual (for 2004 version) I found it on page "5-93".
Have never done this before. Also looking at page 5-94 => Is it really that easy to pull out the gear assembly? Will it all fall in 50 pieces onces pulled out or is it somehow locked together? As far as I believe I need to pull all this out to get the bearing out but I hope I am mistaken :)

If it really IS the bearing I suspect. Apart from what the manual tells me to renew is there any advice for extra things once I get in there?

Bike is near the 80.000 km mark.
At least I hope it's a bearing and not the gearbox itself? But when not in gear it shouldn't be?...
 

Gary in NJ

Junior Member
Site Supporter
Hold-on there!

As the chain passes the counter-shaft sprocket it makes a rather tight turn. The clicking you are hearing are the chain rollers compressing and uncompressing. If you want to confirm this, loosen the chain a raise it away from the front sprocket...then turn the front sprocket by hand to see if the noise is gone.

Also, if you look at that drawing on page 5-93, you will note part number 11, the shift fork. I believe that this part alone keeps this axle assembly from just sliding out. I could be wrong, but I believe that the case has to be split in order to service the transmission.
 
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MrMogensen

... That's me!
Ah yes good idea. That would defiantly settle if it's behind the sprocket or not... hoping you are right!
I am pretty sure it's not just chain-chattering (or as you better explain it with rollers compressing and so on),

Will do it tomorrow evening - I packed away the tools outside before dinner and too comfy now :oops:

The old car needs a trip to/from work tomorrow anyway (been parked for almost 2 weeks because we bought an electric).
 
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MrMogensen

... That's me!
Chain and sprockets should be quite alright. Been using Scottoiler the last 1 1/2 year after I installed a fresh chainkit.
Will report back tomorrow - thanks!
 

TownsendsFJR1300

2007 FZ6
Site Supporter
Plus 1 on Garys assessment.

A worn sprocket/chain will make all kinds of racket.. It's EXTREMELY rare for that bearing to fail, even with over tightening the chain.

And correct, to replace that output bearing requires case splitting..

I'd loosen the rear wheel, lift the chain from the front sprocket and check for looseness, roughness etc.

Lastly, that front sprocket nut has been known to come loose... Check the torque on the nut while there..


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MrMogensen

... That's me!
You must have been right both of you...:cool:
Slackened the chain so I could squeeze it off the sprockets and all seemed fine. Chain back on and tightened it as close to spec as I could. Only regular chain-chatter now when manually spinning the rear wheel - no clickclickydyclick!
Must have never tightened too much even though it‘s down to half a mm or so.
Thanks for helping me get rid of those awful thoughts in a hurry. Sometimes quite nice to work on the bike (when it’s planned). Next winter I am going to check and adjust valve clearance for the 3rd time in my 12 years on this bike. But opening up the gearbox - really no thanks!
 

TownsendsFJR1300

2007 FZ6
Site Supporter
Yep, my chain has to be 2" , NO less, or it's extremely noticeable...
And it doesn't like being dry..

You probably won't need to re-adjust those valves, probably get by with a check.. :)


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MrMogensen

... That's me!
Yes 1st valve check was still within spec.
2nd one (4years later) I changed/adjusted a little more than half of them and could really feel a difference - felt like a better engine more rev-happy engine.
So maybe still within spec?
On upcoming pre-seasons check, while I am in there, I will make sure all valves are as close to middle spec as possible. If it’s too close to be out of spec I just have to open up too soon :rolleyes:

Thanks again!!
 

TownsendsFJR1300

2007 FZ6
Site Supporter
Kinda surprised you had so many to adjust.. Too loose or too tight?

My first (and only) adjust was last year (at 26,600 miles) and I had one exhaust (cyl #4) tight (beyond spec's) by .001". Almost passed on the adjustment, but it wasn't worth possibly burning a valve..


*Now I do run Yamaha's RingFree fuel additive in everything I own and rarely go over 8k RPMs...
I believe that helps keep the carbon down, (loosing up tolerances) and most definitely helps with the fuel system. It's NOT a stabilizer.

I use it in all my customers small machines with definite improvement (chain saw's, concrete saw, weed eaters, generators, etc) in performance..

Plz post back how the valves checked out, just curious...

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MrMogensen

... That's me!
I ran through my older pictures because I knew I made a decent setup to help myself out. This is from 2016 on the 2nd valve clearance check. When I look at my scribble I actually think i might have changed much more than half (maybe all) valve pads.

EDIT: The INTAKE/EXHAUST valve clearance table is on page 3-16 in the 2004 Service manual.

The most local Yamaha dealer traded in valvepads with other sizes for a small amount of money.

As far as I remember/understand the circled digits was my measured clearance and the non-circled digit the valve pads thickness. This helped me in replace with valvepads that made med end up right in the middle of the recommended window. :cool:
To the left I wrote INTAKE and EXHAUST and just below that the "within-spec" numbers.
And as you can see I was a good boy and made sure that every valve-lifter was put back in the same spot...:) Not sure if it would make any particular difference but it was the right thing to do.

I guess at this time my bike was around the 55-60.000 km mark so quite a lot more than yours (Townsend).
Not sure how often "rarely over 8k RPMs" covers but I guess these sunny days I let it strech out more than that several times a week. Every day from work there a looovely big U-turn followed by a 3-400 metre straight before going on the highway. :p
Right after I did that 2nd check back in 2016 I was at a motorcycle course (United Danish Motor Association - or however to translate it). I remember the bike felt so damn good...
It's very hard to guess if it's still as good? If the valves clearance has become close to or a little out of spec it has happened so slowly that it's almost impossible to notice.

Have attached a picture - hope it works!
 

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TownsendsFJR1300

2007 FZ6
Site Supporter
Wow... I'd bet they likely we're very close to spec when you got the bike...

I'd think, being you got them in spec's last time, few, if any will need adjustment.

I guess we'll see.. :)

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