Skipping and clacking at low speed

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Spork

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Jun 17, 2015
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Location
Chicago, IL
Ok so this happens on occasion when doing low-speed clutch work.

The typical situation is that I need to slow down to about 10mph from like 20mph or so. So I pull in the clutch, shift to 1st, and then (while still rolling at about 10mph, or less) slowly release the clutch and throttle (try and keep it at about 2.5K or a little higher, say 3k rpm). What happens next is when the clutch begins to engage (near the end of the travel) I feel in the pegs (and less so in the handlebars) a regular pulsating sensation and hear a "clack-clack-clack", the bike doesn't too jerk violently or anything, but i could mistake it for lugging if it wasn't for the fact I have the RPM at or near 2.5K.

If (while I am still rolling) I pull in the clutch, it stops (the noise, the tapping, everything), and if i begin to re-release it, it usually stops and (sometimes) starts again. If I stop the bike completely and then start moving again, it disappears.

Note, I've never fully released the clutch when this is happening, as soon as I feel it I immediately pull it in and try to re-release it. It feels almost like something is skipping or not catching. I'm not sure if this is just lugging or something else, but my experience with lugging is that it i was a bit more jerky and at lower RPMs. I know the FJR hates traffic, and the throttle is a bit on/off so modulating is not the easiest in traffic.

Today I did some low speed riding and I think driveline lash might have something to do with it too. At low speeds (<10mph) with the clutch in for about 4secs or so (think rolling through a stop sign after almost stopping and then starting again), when I slooooowly release (like msf "I'm trying to find the friction zone" style) and caaaaarefully give it some gas I can sometimes feel a light "bump" from what I perceive is the slack being taken up before the bike begins to move and it feels similar to (but much less in amplitude) the clack clack clack when the issue comes up. I figure that if there is something up with the final drive or joints, I'd feel it much more often, and if it was the tranny it would have other symptoms like slipping out of gear under load, or mis-shifting. So perhaps when the clutch joins under the aforementioned conditions, the free-play in the lash let's the clutch spin unrestricted and then when it hits the end of the lash, it starts skipping due to the sudden resistance. Still though the clutch doesn't slip when i try to make do so, shipting to in 5th and opening the throttle to increase the load, so im kinda miffed.

My approach is to open the clutch housing check the plates and replace with a new model assist setup (was gonna do it anyway) and see what happens.My concern is that the tranny dogs are getting worn, but I'm not familiar enough with bike trannies to diagnose.

What are your thoughts?

 
How many miles on it? My first guess would be clutch plates. Might be worth having a look and maybe taking them out to clean crap off them and an oil soak before putting them back. Probably not excessively worn unless you do a lot of slow speed stuff while feathering the clutch. Maybe check out U-joint as well. Don't think it's transmission. Good luck!

 
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I was thinking U-joint, except for "If I stop the bike completely and then start moving again, it disappears." I don't see how U-joint noise would stop after the bike stopped and then not come back, as the U-joint is still driving the bike...

Does the rate of the clack change with engine speed, or with wheel speed? That will tell you if it's (most likely) clutch or U-joint.

Warped rotor? That might make the pulse, and the clacking could come from disc rivets, which have play in them on floating discs.

Feeling it the pegs puts me back to U-joint, though.

 
Thanks for the replies,

17K miles, owned it since about 6K

I've ridden about once a week 24 miles round trip in Chicago stop and go traffic (12 miles in 45 minutes), that's a lot of clutchwork between 1-2 gears. lots of "rolling stops". This has been going on for about 2.5 years.

To my memory, it has gotten progressively worse, and by that it happens more often. I don't know if this is relevant but the clutch seems to engage at the end of the release (like the last 1/4 or less).

So far my solution is to pick up a XSR tomorrow (new 17) for the city and put the FJR up to take a closer look.

The part that messes with me is that I have switched to Touring, I've been careful to watch the rpms as I release the clutch(2.5k with a steady application of throttle to keep it it above 2K, and it still happens.

Ugh...

 
May be worth bleeding/changing the clutch fluid. The clacking sound you describe is what my AE produces when there's a problem with the fluid.

 
Clutch discs are easy to get to so you can examine them! Won't even need any new gaskets or anything.

 
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I was getting the same mechanical sounds out of my clutch. Now I have no clutch. Yesterday I started the bike to move it out of the way. With the clutch pulled in I dropped into first gear and it engaged immediately and the bike stalled. All this while the clutch was pulled in. It has been progressively getting worse and now it doesn't seem to work at all anymore.

2015 with 1,215 miles on it.

Dammik,

 
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I was getting the same mechanical sounds out of my clutch. Now I have no clutch. Yesterday I started the bike to move it out of the way. With the clutch pulled in I dropped into first gear and it engaged immediately and the bike stalled. All this while the clutch was pulled in. It has been progressively getting worse and now it doesn't seem to work at all anymore.
2015 with 1,215 miles on it.

Dammik,
Just because the clutch lever is pulled in does not mean that the clutch plates have been disengaged.......

I guess the easiest way to check is to open the clutch cover and observe the operation.

 
It was definitely progressive. It started to happen more often. I'm going to do the updated clutch anyway (with the engine assist) so I'll be in there to take a look.

 
Bump,

Ordered parts for the slipper upgrade ($395) ... more to come, I'm hoping that this is limited to worn plates, since some folks have been talking about wearing down my transmission dogs.

 
Is there a slipper upgrade thread that I missed along the way. Has anyone documented how it's done. I remember FredW saying he did the job but don't recall a thread. Maybe I just ignored it.

Dave

 
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Is there a slipper upgrade thread that I missed along the way. Has anyone documented how it's done. I remember FredW saying he did but don't recall a thread or maybe I just ignored it.
Dave
It just never ends does it?
tonguesmiley.gif
Oh yes there is. I'm sure someone will point you (and your wallet) towards that thread soon enough.

 
Not only detailed descriptions but also a good You Tube video produced by Two Wheeled Obsession (Brian). Try Google, I'm sure it will all show up.

 
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