How much transmission slack is normal?

[Daniel_Aus]

Hi all,

Another FZ6 newbie question. My transmission sometimes cluncks when taking off in first gear. I'm not talking about the clunk from neutral to first. When stationary and in first with the clutch pulled in, as I release the clutch and begin to accelerate I sometimes get a heavy thuck in the engine.

I know there is naturally slack in the system but just wondering if others have it to the same degree? This is not the first inline 4 cyl motorcycle of similar capacity I've owned but it sure has a few quirks.

2009 fz6n with 22000kms. All other gears seem fine and it doesn't do it every time.

Thanks

 

[red_rock_beetle]

personally i wouldn't worry about it, its whining noises and gritty feelings i would worry about, i think that slack is more pronounced due to the difficult throttle control especially at higher RPMs

 

[greg]

do you mean when you change into first gear?

other things could be excess slack in the chain, or worn cush rubbers

 

[Ssky0078]

personally i wouldn't worry about it, its whining noises and gritty feelings i would worry about, i think that slack is more pronounced due to the difficult throttle control especially at higher RPMs

Why would you worry about whining? I just got my '08 FZ6 with 7000 miles. I have noticed a whining that is primarily present at over 3000 rpm on up. I stopped by the local bike shop and they told me due to the miles that my bike was like new and not to worry about it. They said it is probably just the nature of my bike and made reference to the primary gear/sprocket (??) like just producing the noise because his gsxr1000 did that.

The whining does go away when I pull in the clutch (disengage)

 

[Ssky0078]

Hi all,

Another FZ6 newbie question. My transmission sometimes cluncks when taking off in first gear. I'm not talking about the clunk from neutral to first. When stationary and in first with the clutch pulled in, as I release the clutch and begin to accelerate I sometimes get a heavy thuck in the engine.

I know there is naturally slack in the system but just wondering if others have it to the same degree? This is not the first inline 4 cyl motorcycle of similar capacity I've owned but it sure has a few quirks.

2009 fz6n with 22000kms. All other gears seem fine and it doesn't do it every time.

Thanks

I adjusted my clutch lever a little bit and my take offs got a lot smoother, no more clunk at the end fo the clutch lever travel if I wasn't paying full attention on the final release of the clutch lever. I never felt any "clunk in the engine" but rather it always felt like from the transmission and the clutch grabbing a little hard due to my noob skills and the clutch setting. The only other clunk I felt was going from 1st to 2nd as the shift bypassed Neutral. It made me think of my old car that had a shift lockout to prevent you from dropping it into first at anything over 5 mph.

 

[Daniel_Aus]

do you mean when you change into first gear?

No, I'm familiar with the normal clunk into first gear. That's fine.

I never felt any "clunk in the engine" but rather it always felt like from the transmission and the clutch grabbing a little hard due to my noob skills and the clutch setting.

Sorry, I worded it badly in my post. The clunk is not in the engine, it's in the transmission. And it is somewhat like you described - a clunk at the end of the clutch release in first gear, just as the drive train begins to engage. It feels like a big piece of heavy metal clunking up against another big piece of heavy metal LOL (slack being taken up?). It's probably normal but I just haven't felt it so pronounced on other bikes. I'm going to try and work out exactly how to create the effect because like I said it doesn't happen every time. It must be something to do with my clutch and throttle control.

I wondered if the front sprocket might be loose but checked and it looks good.

Just wanted to check if other FZ6 owners experienced the same thing. One of the other reasons I have been concerned is, as I've explained in another post, I also have a kind of "ticking/knocking/pulsing" feeling coming through the chassis when the bike is idling, like something is loose and knocking around or against something! I wondered if these were related.

The two mechanics I've shown reckon it's fine but neither of them really took the time to sit there and pay attention to it.

 

[Ssky0078]

I ended up using the manual and following the directions which I think was "B" in teh diagram of rotating from the top down toward the seat (or if looking at the bars from standing to the left going clockwise). It took the sticky point a little closer to the handlebar and gave me enough time to do a controlled relase of the clutch till fully engaged.

I no longer have that clunk type feel at the very end of the clutch release.

Next step is to get some clutch lube and do that job as my clutch is still a little sticky and not as smooth as I would like.

 

[TownsendsFJR1300]

No, I'm familiar with the normal clunk into first gear. That's fine.



Sorry, I worded it badly in my post. The clunk is not in the engine, it's in the transmission. And it is somewhat like you described - a clunk at the end of the clutch release in first gear, just as the drive train begins to engage. It feels like a big piece of heavy metal clunking up against another big piece of heavy metal LOL (slack being taken up?). It's probably normal but I just haven't felt it so pronounced on other bikes. I'm going to try and work out exactly how to create the effect because like I said it doesn't happen every time. It must be something to do with my clutch and throttle control.

I wondered if the front sprocket might be loose but checked and it looks good.

Just wanted to check if other FZ6 owners experienced the same thing. One of the other reasons I have been concerned is, as I've explained in another post, I also have a kind of "ticking/knocking/pulsing" feeling coming through the chassis when the bike is idling, like something is loose and knocking around or against something! I wondered if these were related.

The two mechanics I've shown reckon it's fine but neither of them really took the time to sit there and pay attention to it.

There shouldn't be any clunk AFTER YOUR IN FIRST GEAR. Even with a sticky clutch cable, it would grab but definitly not clunk.

How did you check the front sprocket, with a torque wrench?

If possibly AND SAFELY, you may try putting the bike on the centerstand (with someone on it), kick up the side stand, start the bike, release (after the first gear clunk) the clutch and see if you can pinpoint down the area.

If you can post a video/sound would help as well.

I don't know the condition of your chain but if you have a badly seized link, it can make some bad noises, vibes (never heard it called a clunk thou...)

 

[Daniel_Aus]

After riding and testing this a bit today, I think the 'thwack' (that's the best word for it I think - it's not really a 'clunk') can be recreated by being in first, accelerating and releasing the clutch somewhat so you start moving, then pulling the clutch back in and letting the engine spin down, but before it gets to idle, release the clutch and start accelerating again. This seems to pull up some slack that must build as the engine is spinning down and results in a palpable noise and feeling in the transmission.

I reckon it's fine.

 

[greg]

Only thing you could check is your cush rubbers in your rear wheel. Not sure how long they last but I've got 30k miles on mine and they're still fine.

 

[TownsendsFJR1300]

Only thing you could check is your cush rubbers in your rear wheel. Not sure how long they last but I've got 30k miles on mine and they're still fine.

+1 ^. Being its used, someone could have had the rear tire off and messed with the rubbers, may be missing one, who knows until its apart...

Did you look closely at your chain for any kinked links? One link, badly froze/ kinked, will POP and possibly release(straighten out) when starting in FIRST GEAR as you have the most pulling torque then...

I do remember and posted when you got the bike and the knocking coming thru the foot pegs. What was the outcome of that? It could very well be related...I do hope this isn't related being a bad transmission bearing/gear. Did you get an extended warranty with it?

Can you video tape (with audio) the issue?

 

[Daniel_Aus]

I had another Yamaha mechanic take a quick look at the bike idling and he felt the bike at a few different points and said the "knocking/tapping" was fine and nothing to worry about. I was skeptical though because he didn't really take his time, but seemed to think it was absolutely normal and proceeded to tell me about all the different bits of an engine moving against each other etc..

In terms of the slack and "thwack" in the transmission, I really don't think it's the drive chain. I could be wrong, but it sounds and feels like it's IN the transmission - a bit of slack being taken up between the gears, which I think is normal in a transmission isn't it? I'll try and take a video when I have time so you can hear it.

I think I'll take the bike to another different mechanic to get a third opinion on it. It'll be under 3 month stat warranty for another month and a half.

 

[deeptekkie]

FZ6 bikes just have a clunky transmission, howbeit nearly bulletproof. IMO don't worry about it. Safe riding!

 

[TownsendsFJR1300]

FZ6 bikes just have a clunky transmission, howbeit nearly bulletproof. IMO don't worry about it. Safe riding!

From his earlier post:

"Sorry, I worded it badly in my post. The clunk is not in the engine, it's in the transmission. And it is somewhat like you described - a clunk at the end of the clutch release in first gear, just as the drive train begins to engage. It feels like a big piece of heavy metal clunking up against another big piece of heavy metal LOL (slack being taken up?). It's probably normal but I just haven't felt it so pronounced on other bikes. I'm going to try and work out exactly how to create the effect because like I said it doesn't happen every time. It must be something to do with my clutch and throttle control."

It is not NORMAL AFTER YOUR ALREADY IN GEAR and starting to move to have gears (or something) to clunk together.. It sounds as if something in the gearbox is worn out.. We're NOT talking the first gear from neutral clunk, he's already in gear..... Its quite possible the PO abused the bike, burn outs, etc and caused excessive wear on the gear box. As I re-call you also have a knocking sensation coming thru the rubber mounted foot pegs, again, that is NOT NORMAL..

Find another FZ and ride it, bet it doesn't do it. I can guarantee it will get worse before it gets better....Sorry, just MHO with 36 years wrenching on bikes (mostly Yamaha's, including gear boxes). Mine doesn't do it either, 14,000 miles on the clock, 10,000 of them mine..

 

[Ssky0078]

Did you try an oil change?

I did that today and rode for about 15 miles afterward. I seemed to shift a lot smoother. The old oil that came out was black as night.

 

[Daniel_Aus]

Did you try an oil change?

I did that today and rode for about 15 miles afterward. I seemed to shift a lot smoother. The old oil that came out was black as night.

The oil is good and shifting is smooth as a baby's behind. I went for a spirited ride in the twisties yesterday and can affirm that the gear box feels perfect and deals with anything I throw at it with enthusiasm :BLAA:

This is just something that occasionally happen in first gear when taking off. A little 'thwack' noise in the transmission and the feeling of slack being taken up.

I am pretty pedantic with stuff like this and tend to feel and hear every little thing and wonder if it's broken (as this is a new bike for me). I will take it to another mechanic for an opinion though as it's only under warranty for another month and a half.

 

[deeptekkie]

I used to have a smaller bike that did this and it had a tooth gone off one of the gears.

 

[SweaterDude]

are you sure you're not just dropping the clutch at too high of an RPM. If its at take-off you could just be dropping the clutch, if not at take-off it could just be the jerk from the fuel-cut that is inherent of the FZ6, or that when you pull the clutch the resistance on the engine with the clutch engaged is not relative to the resistance on the wheels and the discrepancy could be causing, although again a "thwack/clunk/knock" should not be occurring if you are being smooth on the clutch.

just thought of something else. have you had the clutch itself looked at. If fragments of the clutch plates are floating around they could make some noise, but once moving quiet down, but probably still no "knocking" sound.

and does it only happen from a stop. or you said something about pulling the clutch and releasing again: try doing this in all gears since your take-offs are always in first, you cant simulate a huge positive change in inertia like that in the other gears.

 

[Daniel_Aus]

try doing this in all gears since your take-offs are always in first, you cant simulate a huge positive change in inertia like that in the other gears.

Good idea! That might tell me if it's an actual problem with first gear itself or it's just the transmission in general (I suspect the latter). I can recreate the sound/feeling by coming to an almost stop (still rolling slowly), clutch in, RPMs almost down to idle, then accelerating and releasing the clutch. As you say, there's a change of inertia in the transmission so I would expect some slack to be taken up - just unsure if it's normal for a bit of a noise to accompany it sometimes.

FWIW I am fairly smooth and don't drop the clutch when I get this effect.

I used to have a smaller bike that did this and it had a tooth gone off one of the gears.

What other symptoms would there be of a missing tooth? There doesn't seem to be anything amiss with any of the gears apart from what has already been described. Once the bike is moving it powers through the gears, up and down, without any issues.

 

[petaminox]

Sorry to hijack this topic, but I have a similar condition. While the engine is in any of the gears, but clutched in such that engine RPMs are at idling range, if I blip the throttle, I can feel the chain being tensioned. Is this normal?