KTM 990/950 Adv thread

[junkmanjoe]

my clutch lever feels soft, and gear changes are clonky...whats the go boys...


JMJ

[Crisis management]

my clutch lever feels soft, and gear changes are clonky...whats the go boys...


JMJ

First bleed it, maybe change the fluid (it may be old) and then have a bit of a look at the slave cylinder as they are a known weak point, I believe the fix is an aftermarket slave cylinder.
Have a look on the OC hall of wisdom as it is all documented there.

[Waihou Thumper]

my clutch lever feels soft, and gear changes are clonky...whats the go boys...


JMJ

The wise man in the Waikato?

[junkmanjoe]

First bleed it, maybe change the fluid (it may be old) and then have a bit of a look at the slave cylinder as they are a known weak point, I believe the fix is an aftermarket slave cylinder.
Have a look on the OC hall of wisdom as it is all documented there.

yip i posted the prob up there and good feed back about possible causes.


JMJ

[dino3310]

my clutch lever feels soft,
JMJ

just have a play with it mate it will soon harden up

[junkmanjoe]

just have a play with it mate it will soon harden up

you going to need to do a far bit of stroking to fix yours mate........

[dino3310]

you going to need to do a far bit of stroking to fix yours mate........

thats just down right nasty mate......
i like nasty

[Woodman]

Come on Guys, neither of you ride DRs anymore so all this manlove talk should stop.................

[Box'a'bits]

Come on Guys, neither of you ride DRs anymore so all this manlove talk should stop.................

Ah, yes, but Dinos got a Honda now. A step too far really...We've all discussed (disgust?) what that can do for a man. And really, what is JMJ compensating for? Its so big. And now he's telling us its really soft???

[cooneyr]

my clutch lever feels soft, and gear changes are clonky...whats the go boys...


JMJ

My clutch stoped working over about 50kms of riding. Noticed that the engage/disengage point was getting closer to the bars until it wouldn't disengage at all. Makes riding around town a bit interesting! Basically it had lost enough fluid past a worn seal that it wasn't working any more. Probably the same for you. Get a 22/23/24mm id 2mm diameter O ring ($0.95 each), pull the two bolts that hold the slave cylinder on, one circlip to remove the piston from the housing, clean, replace O ring, bleed the system and away you go.

You need to bleed the cluch from the slave cylinder. Get a 50mm or larger syringe (know a friendly nursey ) and a bit of tube and force the mineral oil (do not use brake fluid!!!) in at the slave cylinder bleed nipple with the master cylinder cover off (clean out the master cylinder first). You may then have to work the clutch leaver a few times to get air to come back up the line (it is very steep so air not likely to go down), then do a couple of "normal" i.e. pressurise the system with the clutch lever and bleed out the slave nipple. This is cause the slave nipple is the highest point in the slave cylinder for an air bubble to sit in. I though this whole process was going to be a bit of a nightmare given the Yanks dribble about it all but it was a piece of cake.

I got a 150ml(?) bottle of Spectro mineral oil specifically for Magura clutches on KTMs for $8 for the local bike shop that should give me a two or three fluid replacements. Way way cheaper than the Motorex 75 fluid that cost $25 for the same stuff. Some use baby oil which is a mineral oil in an emergency - get the scented stuff and your clutch will smell nice I used a 22mm ID O ring and it seems to be working fine (done 500kms since replacing) but it should probably really be a 24mm ring. Take the clutch piston when you go shopping to be sure. 2mm diameter is important though.

I've had a look at the system and cant see for the life of me why the piston would twist in the bore as suggested by some on ADV rider. The piston has a hole that sits over the clutch push rod when in the slave cylinder in fitted up so I'm buggered if I can see how it would twist in the slave cylinder bore. The plastic spacer could warp with heat and while the slave cylinder seals against the spacer seals in the engine oil, a warped plastic spacer should have no bearing on how well the slave cylinder piston seals i.e. how the clutch works. So after actually pulling it to bits and having a look I'm very much inclined not to buy a US$200+ replacement slave cylinder. I'll just carry a couple of spare O rings and the remainder of the mineral oil around with me - takes up bugger all space.

The KLR boys are going to love this post - baby oil, slaves, nipples, working the lever, bores, etc!!!

Cheers R

[Fluffy Cat]

The system for the clutch is hydraulic and made by Margura better known for MTB applications. The master reservoir is kind of small and the system uses mineral oil(just like MTB's). The oil goes off quite quickly compared to a DOT 4/5 etc systems and, needs to be replaced more often. The slave has also been improved on the 990 versions.
1. Unbolt slave inspect, leaks/damage at seal?. Replace if stuffed. If it looks ok no damage to o-ring goto 2. Make mental note to buy improved slave.
2. Replace fluid with mineral oil, you can use MTB stuff if you cant find any. Shimano do good stuff. Make mental note to replace often.
Hope this helps.
Any errors in this are due to me been knackered after changing the tyres on me BRP I am crap at changing tyres and should know better but i want to play on the weekend...cheers.

[junkmanjoe]

okies ...thanks heaps guys.. just may be rolling sat after noon...
ill pop in to lins autos..he got more o rings than a paddock fill of sheep....

there is oil under neath the unit so it coming from some where.

cheers
JMJ


P:s.. Black klrs suck rabbits balls.......

[warewolf]

I got a 150ml(?) bottle of Spectro mineral oil specifically for Magura clutches on KTMs for $8 for the local bike shop that should give me a two or three fluid replacements. Way way cheaper than the Motorex 75 fluid that cost $25 for the same stuff.

Use leftover fork oil...

The system for the clutch is hydraulic and made by Margura better known for MTB applications. The master reservoir is kind of small and the system uses mineral oil(just like MTB's). The oil goes off quite quickly compared to a DOT 4/5 etc systems and, needs to be replaced more often.

Que? Not only is that news to me, it contradicts everything I've read about them! Why do you think it goes off?

Advice on KTM forums says the opposite. Brake fluid is hygroscopic so needs to be changed every year, more often when racing. The accepted wisdom for hydraulic oil clutches like Magura's is don't touch the buggers unless you have problems. The clutch simply isn't under the kind of stresses brake fluid is: no wicked heat, bugger-all pressure, the fluid doesn't readily absorb water, the slave piston seals aren't exposed to so much forced-in dirt/mud/grime.

My personal experience reflects that; I can tell when brake fluid deteriorates, but never had a problem with Magura clutches and never changed the fluid. (Except when I had a mechanical failure - hose unscrewed from the master cylinder.)

The KTM specified service interval for the Magura hydraulic clutch fluid is... none.

[Edit: Ah, I think I see the problem. Ding! (Where's the lightbulb smilie?) Newer mtb BRAKE systems are using mineral oil instead of proper brake fluid... yeah, I can see it being way inferior in that application. But mtb's don't have clutches, right?]

[NordieBoy]

The hydro Magura on the Nordie was still sweet 3 years after I installed it.

[Monstaman]

my clutch lever feels soft, and gear changes are clonky...whats the go boys...


JMJ

JMJ ...I had a quick look at my bike to try and help you ... I can't find any oil on mine ... it appears to be a fairly reliable looking cable, the DR650's have them.

Hope this helps