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Discussion Starter #1
I bought a 95 Sprint 900 a year ago which had spent a few years sitting around unused. A persistent problem has been the clutch not seeming to disengage fully. On the centre stand I am unable to shift the rear wheel by hand with the lever inif it is in 1st gear. Going into 1st gear is acompanied by a loud kerthunk and gear changes up and down are mostly are clunky. Sometimes this does not occur but I have not figured out what the trick is. Whether the engine is hot or cold makes no real difference to the problem. Otherwise the clutch feels fine in terms of it feeding in progressively.
I have flushed through and bled the clutch hydraulics and engine oil is Motul synthetic - these measures made no difference.
How "normal" is such a clunky gear change and would it be worth my while pulling the clutch apart? What is usually the problem causing these symptoms?
Thanks for your advice. I have done a bit of searching on here and couldn't find this issue clearly being addressed.
 

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Are the rubbers in the back wheel still ok? This could be where the noise is coming from?
My 98Sprint, if let to sit for long periods will also bind. The first gear is always a clunk From the clutch grabbing, I have started the bike in gear once only to be lunged froward.

You may also have to check clutch plates for distortion, maybe the previous owner used friction modified oil which is counter productive.
 

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Discussion Starter #4
Are the rubbers in the back wheel still ok? This could be where the noise is coming from?
Thank you but it really feels like clutch problem. I can feel it in my left foot when I change as the gears don't want to mesh neatly. If I don't place much load on the system shift early it is less noticeable but then I have my other problem of it not pulling well from low revs...
Maybe it could keep on like this for years but it just irritates me.
 

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Maybe you need to put a seal kit through the clutch master and slave. Is your clutch hose braided stainless steel like mine? If not I wonder if you have hose swell.( not sure if thats the techincal name for it) It's a pity no ones made a dodad that can be screwed into master cylinder and it shows you what the pressure is when grab a hand full of clutch or brake.
 

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Discussion Starter #8
That may well be what I need to do.
This afternoon I got curious and took the clutch cover off. I discovered that there was a layer of white gunk at places around the inside of it as though at one stage there had been water getting in. It is not mixed with the oil and there is no evidence of the white stuff when draining the oil from the sump or in the filter, so that is a mystery. I took out the clutch plates and they seem in reasonable condition - no warpage in the plain plates and the friction plates are at spec thickness. There is quite a bit of ridging of the slots in outer drum and centre so I will clean that up with a file, stick it all back together and clean out the cover.
There is about 3.5 mm of travel in the pushrod as the clutch lever is pulled in but how much pressure is there to act against the springs is the real issue and as you say Crooky, thats what we need to be able to test.
Will keep you posted.
 

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White gunk is emulsified oil from the breather...moist air condenses out and that's what you get over time..you see it on the under side of some oil filler caps etc too when I had my cover off for powder coating the plate on the inside looked like this http://mottleybiker.com/page25.htm so don't worry it's a common thing ;-) my first port of call for clonky gear changes would be in this order chain adjustment (min 35-40mm at the tightest spot), oil change (the level is important too much and the clutch will drag) and maybe while at it take the primary cover off and check the clutch push rod is straight, clutch bleed and or strip and clean the slave cylinder, clutch springs...

Hope you get it sorted
Mot
 

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Discussion Starter #10
Thanks Mot, I am glad the white gunk is no more sinister than emulsified oil! I will follow through with your suggested steps and look forward to smoother shifting. You have a great website too so that will help me keep the bike going strong. Cheers
 

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Discussion Starter #11 (Edited)
Just to follow up with this, I am now enjoying much smoother shifting. What I did was using a small fine file, I smoothed out the ridges in the slots in the outer drum and centre. I then used brake cleaner and a toothbrush to clean up the friction and plain plates, coated them in fresh oil and reassembled them in not quite the same order as they came out. I noticed that when pulling in the clutch lever, a significant gap appeared between the pressure plate and the first friction plate. To me, this indicated that the hose and cylinders were not the problem. I pulled apart and thoroughly cleaned the damper and cover which had a spectacular amount of emulsified oil and apparent moisture. I was careful with the level when refilling the engine oil but I had previously excluded that as a possible cause. As I had also fixed a no start problem which turned out to be a faulty crank sensor, I took the bike for a ride. Much more pleasant to not feel as though my left foot is doing damage with each shift!
 
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