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Discussion Starter #1
OK - some of you may know I recently destroyed my clutch on the lanes in Wales. Clutch plates shattered, blistered and distorted. I have seen this happen before on RiderBobs 990 in italy. At that time everyone blamed Bobs heavy handed clutch technique :D

So - my clutch went exactly the same way after less than 3000 miles. I have 3 theories.

1.
My heavy handed clutch action simply wore it out.

B.
I assembled the clutch wrong when renewing it and this accelerated the wear

3.
Cheap crappy clutch kits from KTM

C.
Oil starvation and so over heating caused by a blocked clutch oil jet


Here's my answers:

1.
yes - at time i give the clutch a hard time but I would expect it to simply wear away - not shatter and crumble into pieces. I wouldn't mind so much if I just wore it out but most of the plates had plenty of material left on them - they were just in lots of pieces.

B.
I'm seriously considering this. I noticed when I rebuilt the clutch this time that the outer pressure plate can sit slightly proud because the inner teeth don't engage properly. I managed to bolt it up like this then noticed there seemed to be a gap that didn't look right. I unbolted it, twiddle the pressure plate and it 'snicked' into place a good 2 or 3 mm further.

This would maybe explain why the outer plate was worn away completely and would also suggest a big build up of heat to knacker the rest.

3.
Cheap clutches from KTM? Well they aint cheap in money terms and I would expect the kit to be the same as used in new bikes - some of which go on for tens of thousands of miles

C.
Clutch oil jet ................... YEP - I go for this one.

Have you seen the size of the hole in that jet? It's a .30 jet (whatever that means) and is stupidly tiny. Although I have cleaned mine in the past it wouldn't take much to block it .... theory is there shouldn't be anything big enough in the oil but .. .. ..

So - I have purchased a jet size .60 from Ebay. £2.99. Fairly easily fitted (I have a secret tool for jet removing - only works sometimes though and on this occasion bluetack was better :rolleyes:)

The larger jet is twice the size and should flow far more oil. I had read this would casue all sorts of problems from not getting neutral to difficult gear selection and clutch judder.

Having spent a good half day out on some local lanes with MartynHo I can confirm no problems or symptoms at all. I covered around 150 miles with a mix of fast roads and rock strewn Yorkshire lanes.

Selects all gears fine - neutral is easy enough and the clutch action great.

I have no idea if this will do any good at all. But at £2.99 for a jet off Ebay it's gotta be worth a try.

I think I can relax a little now and not worry about the clutch. I've got decent Kevlar plates in there, decent oil and hopefully plenty of it.

Pete
 

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B.
 

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Discussion Starter #7
obviously Timpo put it in the right way
What are ya trying to say? :D "I'm glad Pete didn't do mine" ................. ;) :rotflmao:

I've learnt a lot from this clutch failing and hopefully others on here will benefit from it. It'll be a while before I trust my clutch again and I'll be taking the cover off quite a lot to keep an eye on it.

I'm trying to think of a way of checking the amount of oil getting to the clutch with the bigger oil jet. I can't afford a see through clutch casing unless you want to buy me one in the interests of scientific research?

Pete
 

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I don't think it is this
C.
Clutch oil jet ................... YEP - I go for this one.
The clutch oil jet was originally a blank, and the lubrication it provides is only for the rod, not the clutch itself.

I think option 2 was your correct answer
 

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Discussion Starter #9
I don't think it is this
The clutch oil jet was originally a blank, and the lubrication it provides is only for the rod, not the clutch itself.

I think option 2 was your correct answer
As far as I know the oil jet lubricates the push road and then via centrifugal force comes from the middle of the clutch out onto the plates. Everything I read seems to indicate the issues were the plates - not the push rod.

I'll see how it goes.

Pete
 

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That is correct, but it was not the main source of lubrication for the plates, which are after all in a bath of oil. As I say, it was only introduced for racing, and the original design was no jet at all, just a blank.
 

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As far as I know the oil jet lubricates the push road and then via centrifugal force comes from the middle of the clutch out onto the plates. Everything I read seems to indicate the issues were the plates - not the push rod.

I'll see how it goes.

Pete
Yep.
Woudnt have thought the Pushrod needs much by way of lubrication - it does f-all most of its life.
The oil jet was to get extra oil into the clutch - as shep says. The guys who ran the 950 in the dakar, ran an even bigger jet (finding neutral for those guys.... not something they have much opportunity to worry about :) )
 

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Woudnt have thought the Pushrod needs much by way of lubrication - it does f-all most of its life.
The wear on the pushrod was documented in Pyndons ADVrider thread> http://www.advrider.com/forums/showpost.php?p=5224267&postcount=457
It is a stationary rod in a spinning clutch so is subject to wear. However this does seem to be the main source of lubrication for the clutch according to the Repair Manual
"Oil is conducted to the pushrod and to the clutch
through the injection tube, another oil duct and
the reducing jet."
 

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Discussion Starter #14
The wear on the pushrod was documented in Pyndons ADVrider thread> http://www.advrider.com/forums/showpost.php?p=5224267&postcount=457
It is a stationary rod in a spinning clutch so is subject to wear. However this does seem to be the main source of lubrication for the clutch according to the Repair Manual
"Oil is conducted to the pushrod and to the clutch
through the injection tube, another oil duct and
the reducing jet."
The push rod sits in a bearing at the clutch end - so the fact it is stationery and the clutch is spinning shouldn't matter.

I spent a full day out yesterday. Lots of fast road and lots of steep, rocky, slippery climbs. The clutch performed faultlessley and there were no indications at all that I had changed from the standard .30 jet to a .60 jet. No gear selection problems, no neutral selection problems.

I obviously don't know if I am now getting more oil to the clutch ............ but I am guessing I must be. I keep intending to whip the cover off and see if it looks any wetter :D
 

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Piccy,s as well please, as I am following this with great interest, and having seen the colour of the clutch basket in Wales, would like to visually see the differance, thanks.
 

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Discussion Starter #16
Piccy,s as well please, as I am following this with great interest, and having seen the colour of the clutch basket in Wales, would like to visually see the differance, thanks.
I'll take a piccy tomorrow night ................. the new clutch has now done around 450 miles of which 250 or so was the Lakes trip yesterday where I was my usual ham fisted self with the clutch lever.

Not a sign of slipping or anything. Those back roads were literally full throttle - brake hard - full throttle - gear up, brake, gear down - full throttle. Now I think about it it was all a bit crazy really. To be gunning a 1000cc V-Twin that hard on a public road. We must have been ........

























fookin luvin it !!
 

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I'll take a piccy tomorrow night ................. the new clutch has now done around 450 miles of which 250 or so was the Lakes trip yesterday where I was my usual ham fisted self with the clutch lever.

Not a sign of slipping or anything. Those back roads were literally full throttle - brake hard - full throttle - gear up, brake, gear down - full throttle. Now I think about it it was all a bit crazy really. To be gunning a 1000cc V-Twin that hard on a public road. We must have been ........

























fookin luvin it !!
:Dtight, luv it,... dropped in a 990 rear shock tonight, it has dropped the back end no end, can actually touch the ground with both feet now, an when its on the main stand, the rear wheel is a good four inches off the ground.
Are you still running the 16 x 47 or have you given up on that for the moment ?
 

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Discussion Starter #18
:Dtight, luv it,... dropped in a 990 rear shock tonight, it has dropped the back end no end, can actually touch the ground with both feet now, an when its on the main stand, the rear wheel is a good four inches off the ground.
Are you still running the 16 x 47 or have you given up on that for the moment ?
I'm back on 16/45 at the moment. I wasn't at all happy with the wheel so far forward to get the chain to reach - I was wearing the back tyre out on the shock protector!

I'm probably gonna fit a 120 link chain and put the 47 back on for Ryedale - I'll keep the current 118 chain, standard and 45 sprocket for other occasions - although I can't think what.

Good to hear you sorted you short legs out - maybe we won't be picking you up a lot on the Ryedale eh?

Pete
 

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Discussion Starter #19
Not the best of photo's ................. but here's the clutch after 450 miles. Bit different than last time you saw it eh Surms? :rolleyes:









However - the outer frictionplate material was alarmingly thin, but there again I can't remember how much material was on it in the first place!!

Certainly seems to be more oil around than previously.

I'm guessing all I can do is continue to ride it and see how it goes.

Pete
 

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So - I have purchased a jet size .60 from Ebay. £2.99. Fairly easily fitted (I have a secret tool for jet removing - only works sometimes though and on this occasion bluetack was better :rolleyes:)
Please could you post a picture showing where the oill jet is, and explain how you get it out.
I run an 07 Superduke and have looked where I believe the oil jet is but couldn't remove it, although I hadn;t thought about bluetack.
I want to be sure I am looking in the right place first.

Thanks
MTR
 
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