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Ktm_jack

KTM SX 125 2006 Power Valve issue

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Hi guys, I hope this is in the correct area of the forum.

So I've recently bought my first 2t and needles to say it's not been what I expect when I bought it.. I've had a lot off issues with seized nuts and bolts and generally by the looks of it a poor maintenance schedule.

First off I went to do a quick oil change and the inner clutch case basically fell apart around the drain plug when removing it, 

I've since replaced the inner clutch cover and had to swap over the power valve governor, arm and adjuster. Got it back together and I was unscrewing the adjuster and i felt and heard a clunk (think I unscrewed it to much), the 4 balls that had become unseated. I've taken the cover off and I believe it's back together correctly but the pin that holds them in seems to be relatively loose.. it also feels like there is no real resistance on the power valve arm. I haven't started the bike since doing this as I'm awaiting a new piston to arrive tomorrow hopfully.

 

I have a Video but I'm not to sure how to upload it so can email it if it helps. 

 

Thanks, Jack

 

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The ramp end takes quite a bit of hand pressure to push it down the shaft to free the holding pin. Did it all come to pieces when you removed the pin or did you manage to hold on to it? It should not be loose so you've maybe missed putting one of the spacer bushes back? I suggest you look at a KTM  exhaust control fiche (www.trevorpopemotorcycles.co.uk have a great fiche on line) to make sure you have all the parts and they are back in order. You shouldn't turn the 2 sided adjuster nut out more than 10mm from the mating surface of the clutch cover as you have discovered.  Also, you should never remove the oil level bolt in the clutch cover as it is so easily stripped. The drain bolt is the 13mm one near the gear lever..

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9 minutes ago, 7Tktm said:

The ramp end takes quite a bit of hand pressure to push it down the shaft to free the holding pin. Did it all come to pieces when you removed the pin or did you manage to hold on to it? It should not be loose so you've maybe missed putting one of the spacer bushes back? I suggest you look at a KTM  exhaust control fiche (www.trevorpopemotorcycles.co.uk have a great fiche on line) to make sure you have all the parts and they are back in order. You shouldn't turn the 2 sided adjuster nut out more than 10mm from the mating surface of the clutch cover as you have discovered.  Also, you should never remove the oil level bolt in the clutch cover as it is so easily stripped. The drain bolt is the 13mm one near the gear lever..

Thanks for the reply I really appreciate it,

The pin was loose caught and mixed in with the 4 balls.

Looking at the diagram I think I've got these washers where I've marked.. they was the perfect slight bowl shape so thought thats where they came from. 

I'll remember that for next time thanks, definitely wasnt aware not to remove it that much. 

Yeah since stripping that thread it seems to be really common, feels like I've got a lot to learn with this bike.

 

 

 

20200521_000038.jpg

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Posted (edited)

So you had the 2 saucer shaped washers in the wrong place? Do you still have the clutch cover off? If so there's another part you should replace. Good bikes and easy to work on. Bob

Edited by 7Tktm

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1 hour ago, 7Tktm said:

So you had the 2 saucer shaped washers in the wrong place? Do you still have the clutch cover off? If so there's another part you should replace. Good bikes and easy to work on. Bob

Sorry in advance if I reply twice, I'm not sure what I done but my reply didnt send I dont think so I'll re write it.

Yeah I'm sure the 2 saucer shape washers are in the wrong place, looking at the diagram they sit after the pin, I'm guessing to help keep the pin in place? 

The case is all back on but it's not an issue as it wont take me long to strip it down, I've got a new piston to hopfully put on tomorrow if it turns up anyway. 

I've uploaded the video of how it was as I'm not the best at describing things some times so it might help.. 

 I've also looked online at other pictures and the pin sits really nicely in the groove, mine doesnt sit like this one that I've found at all. 

 

 

 

Screenshot_20200521-013309_eBay.jpg

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Not yet I work nights and have only just got up. Piston should be delivered at about 3 so I'll go out and have another look then. I'm wondering if the spring is possibly stuck on the shaft for some reason and if I could try to compress it a bit more it may release it.. I've been reading lots of different threads and posts and someone had it stuck on a small groove on the shaft so I'll try that 

 

49 minutes ago, 7Tktm said:

Got it fived yet?

Not 

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2 hours ago, Ktm_jack said:

Not yet I work nights and have only just got up. Piston should be delivered at about 3 so I'll go out and have another look then. I'm wondering if the spring is possibly stuck on the shaft for some reason and if I could try to compress it a bit more it may release it.. I've been reading lots of different threads and posts and someone had it stuck on a small groove on the shaft so I'll try that 

 

Not 

 

20200521_160852.jpg

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2 hours ago, Ktm_jack said:

Not yet I work nights and have only just got up. Piston should be delivered at about 3 so I'll go out and have another look then. I'm wondering if the spring is possibly stuck on the shaft for some reason and if I could try to compress it a bit more it may release it.. I've been reading lots of different threads and posts and someone had it stuck on a small groove on the shaft so I'll try that 

 

Not 

 

20200521_160905.jpg

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It doesnt look like its sat right but as much as I try and move it down, play with the spring, I cant figure out how to fix it. As you can see from the last picture it's got to come up a fair bit 

IMG-20200521-WA0007.jpg

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It doesn't matter how much it moves down towards the gear, that's not the direction that the system works in. The shaft bush where the Lever F mounts should be a smooth, shiny and undamaged.  Yours is anything but, which is stopping the system from working. That's your problem. Bob

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Another little update.. hoping I've sorted it. the pin is now in there solid and it's put tension on the arm, and all looks okay I feel much more confident with how it is but the big test will be tomorrow, new piston is on and the head back on with the arm in the fork, so I'll get it all back together and test it out tomorrow. Fingers crossed 

20200521_170616.jpg

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15 minutes ago, 7Tktm said:

It doesn't matter how much it moves down towards the gear, that's not the direction that the system works in. The shaft bush where the Lever F mounts should be a smooth, shiny and undamaged.  Yours is anything but, which is stopping the system from working. That's your problem. Bob

Ah right gotcha, I'll get one ordered and will replace it, I might order a new shaft for it to go on as well as it was very hard to move the parts on there.

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Well see how it works, looks ok. Take it you know for more bottom end you adjust it so the slot as seen through the left hand cylinder inspection cover is at the top and drops down out of sight as you rev the bike then returns back up as you let the throttle off. Did you renew the 'o ring string' as KTM calls it so you can lock up the 2 sided adjuster once you tighten the lock bolt at 4 o'clock.? Easy to do when you have the cover off and adjuster off. If you have issues with the timer, get back to me, I have a good used one. Good luck with it sure you will get it running fine.  Bob

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Posted (edited)
On 5/21/2020 at 6:39 PM, 7Tktm said:

Well see how it works, looks ok. Take it you know for more bottom end you adjust it so the slot as seen through the left hand cylinder inspection cover is at the top and drops down out of sight as you rev the bike then returns back up as you let the throttle off. Did you renew the 'o ring string' as KTM calls it so you can lock up the 2 sided adjuster once you tighten the lock bolt at 4 o'clock.? Easy to do when you have the cover off and adjuster off. If you have issues with the timer, get back to me, I have a good used one. Good luck with it sure you will get it running fine.  Bob

Right.. so shes finally back together and when I adjust the power valve I can see it changes the height of the mark that you can see in the left inspection window, however it doesnt seem to drop out of sight when revving it. Frustrating as it must be connected up correct as when I adjust it moves the mark.

I didnt renew the string o ring, I didnt think to get one.

Edit: I've gone through some other posts and someone had similar but theres fixed when they re tightened the head down. The fact the mark moves up and down when I adjust it makes me think it is connected correctly as surely if it was just pushing on one side, not actually in the fork it wouldnt come back down with the adjuster? Unless it's just coming back down resting on it.. 

I'll take the exhaust off and double check it's in the fork when I get a chance next

 

 

Edited by Ktm_jack

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Posted (edited)

See your photo - do you know how the damage was caused to Lever F bush - I've never seen this before, but knowing how the timer works would suggest this is your problem.

Edited by 7Tktm

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17 minutes ago, 7Tktm said:

See your photo - do you not think that the problem is the knackered bush that Lever F (the cranked lever) runs in? That's why you had a problem putting it back together - if it was working as it should you just put the spacers, springs and bush on the shaft, mount the 4 balls and ramp and push in the locking pin once you've squeezed it down.  

Yeah definitely. The fact it's all linked up and moves when I adjust it but when revving the bike it doesnt actually move it. It must be..

It had no movement from the cup that you mount the balls in.. I was able to push down and get movement from the gear side, but unable to move or press from the side with the balls and ramp. I had to tap it with a rubber mallet to get it to sit properly so the pin would go in the groove properly.. Surely a Bush wouldnt seize it up that much would it?

I'm struggling to find any parts for it, it seems they only sell them as a whole unit. I'll keep searching tomorrow and I'll see what I can find.

 

I'll delete that second post that got put up as well, no idea why it got posted twice 

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Posted (edited)

First, do you agree there's damage to that part and it's not my eyes? You don't need a mallet to put it together! I'm really trying to help but you are not making things easy, adding an extra bit of your problem every thread. Bob

Edited by 7Tktm

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13 minutes ago, 7Tktm said:

First, do you agree there's damage to that part and it's not my eyes? You don't need a mallet to put it together! I'm really trying to help but you are not making things easy, adding an extra bit of your problem every thread. Bob

Yeah I definitely agree that its damaged from the lever and has caused a circular indent in the Bush, looking at the pictures it doesnt look like it sits straight on the shaft, probably due to where its worn and pushed the metal inbetween the Bush and washer

 Sorry for adding to the problem,  I'll try make sure I get everything into one post. I do really appreciate your help.

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Ah, ok - I am just trying to find out if timer is salvageable. See when you hold it, can you push the top part which the ball ramp sits in down towards the gear end - you should be able to compress it smoothly around 5 or 6mm against the spring pressure. If not I have an answer. If you really want to understand how the whole pv system works I can explain it. Bob

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