KTM 125 clutch dragging

Rickyisms
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Rickyisms
Edited Date/Time 8/14/2022 3:36pm
I started feeling the clutch slip my last time riding so I put in a brand new Pro-X clutch kit with springs. I measured the plates before installing to verify they were the correct thicknesses, mines a 2016 so no DDS clutch, the only difference in plates is two thicker steels that go in the middle of the order.

After the plate change I noticed a super light clutch pull, and then when trying to shift to 1st it would stall, can also feel it lurching in gear even with the lever to the bar.

I had no problems like this before swapping the plates, I just knew they were ready to be changed. Bike has a full Hinson setup, basket is not grooved, same with the inner hub and pressure plate. I run a pair of Sunline levers but I never had this problem before changing the plates. Tried a stock lever with no improvement.

One thing I noticed was on the pressure plate there is a small machined dimple, but I could not find anywhere to line it up to. I called Hinson and the guy was super helpful but when I mentioned that mark he didn’t seem to know much about it. I’ve also bled the clutch system.
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Matt Fisher 8/12/2022 4:48pm
8/12/2022 4:48pm
Similar problem with a 17 125. Tried bleeding it many times, rebuilding the master and slave, swapped to a complete Hinson, all to no avail. New master and slave- perfect.
Rickyisms
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Rickyisms 8/12/2022 5:30pm
8/12/2022 5:30pm
Matt Fisher wrote:
Similar problem with a 17 125. Tried bleeding it many times, rebuilding the master and slave, swapped to a complete Hinson, all to no avail. New...
Similar problem with a 17 125. Tried bleeding it many times, rebuilding the master and slave, swapped to a complete Hinson, all to no avail. New master and slave- perfect.
Strange. Will give everything a once over and see how it looks. Just weird because everything was fine before changing the plates. Gonna measure the springs as well, maybe Pro-X isn’t up to spec, they did look slightly different than the ones I pulled out.
Rickyisms
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Rickyisms 8/12/2022 5:33pm
8/12/2022 5:33pm
Matt Fisher wrote:
Similar problem with a 17 125. Tried bleeding it many times, rebuilding the master and slave, swapped to a complete Hinson, all to no avail. New...
Similar problem with a 17 125. Tried bleeding it many times, rebuilding the master and slave, swapped to a complete Hinson, all to no avail. New master and slave- perfect.
Do you remember if your Hinson setup had a machined mark anywhere on the pressure plate or anything in the manual about orientation. I swear I never paid attention to anything like all the other times I’ve swapped plates.
Matt Fisher 8/12/2022 8:44pm
8/12/2022 8:44pm
I pulled the clutch before selling the bike. I can measure anything you’d like. The only instructions were to remove a judder spring, if the bike was so equipped from the factory.



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Bruce372
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Bruce372 8/13/2022 8:17am
8/13/2022 8:17am
I would try removing the slave, pressing rhe actuator all the way back on, then reinstall and prime the line.
Rickyisms
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Rickyisms 8/13/2022 9:29am
8/13/2022 9:29am
Bruce372 wrote:
I would try removing the slave, pressing rhe actuator all the way back on, then reinstall and prime the line.
That was my next move to try, I seem to remember having to do that 2-3 years ago after the bike sat for a while and had a similar feeling at the lever.
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Rickyisms
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Rickyisms 8/13/2022 10:17am
8/13/2022 10:17am
Pressed the piston in and got a bubble or two at the master cylinder. Cycled some fluid through reverse bleeding, no luck.
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Rickyisms 8/13/2022 10:55am
8/13/2022 10:55am
So I decided to inspect the springs, here’s the Pro-X spring next to a spring from my last kit (DP clutches, always had good luck). Slightly shorter than the DP spring. Swapped the DP springs in and made a tiny bit of difference, but I went ahead and adjusted my lever all the way out and now it disengages when the lever is just about to the bar! Good improvement, but I’m still searching for a slightly sooner disengagement.

Thinking of ordering a brand new set of springs as these DP ones have some hours on them for sure.

OEM? EBC springs? Are the Hinson springs really worth the $60?
Bruce372
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Bruce372 8/13/2022 1:23pm
8/13/2022 1:23pm
I would stick to oem springs. We are running prox clutch no problem, I think it came as a kit with springs but can't remember. Maybe I am still on oem.??

Sometimes with clutches, you just have to ride them a little, get some heat and let it sort itself out.

Good luck
Rickyisms
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Rickyisms 8/13/2022 1:43pm
8/13/2022 1:43pm
Bruce372 wrote:
I would stick to oem springs. We are running prox clutch no problem, I think it came as a kit with springs but can't remember. Maybe...
I would stick to oem springs. We are running prox clutch no problem, I think it came as a kit with springs but can't remember. Maybe I am still on oem.??

Sometimes with clutches, you just have to ride them a little, get some heat and let it sort itself out.

Good luck
I’ve done some pulls through a field by the house. Gets maybe slightly better with more time but I really can’t reef on it there for more than third gear.
Rickyisms
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Rickyisms 8/13/2022 1:44pm
8/13/2022 1:44pm
Here is a picture of the pressure plate with the dimple.

Rickyisms
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Rickyisms 8/13/2022 1:58pm
8/13/2022 1:58pm Edited Date/Time 8/13/2022 2:01pm
Pulled the clutch lever on my way out of the garage and it felt better than ever! Tested it around the front yard and engagement and modulation is actually better than any recent memory! Thinking some air finally made its way to the clutch master cylinder. I shot a full syringe through the slave 5 or 6 times earlier and it didn’t help. Patience is an acquired skill.
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Bruce372
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Bruce372 8/13/2022 2:09pm
8/13/2022 2:09pm
Pleased you got this sorted, these issues can often turn into a wild goose chase
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AJ565
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AJ565 8/13/2022 4:03pm
8/13/2022 4:03pm
Zip tie the lever to the bar and let it sit over night with the wheel turned to the right. I’ve had to do this with the front brake on my ‘18 a few times.
FGR01
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FGR01 8/13/2022 4:26pm
8/13/2022 4:26pm
The problem is obviously that the actuation mechanism/train is not pushing the pressure plate far enough to disengage the plates. The question is why. As you've already been messing with, an improper bleed can cause this. However, I'd be measuring the thickness of the total plate stack, old vs. new. I suspect there's a difference that is outside the range of normal wear. And it might just be those 2 extra thick plates. Sounds like you might be better off replacing those with 2 more the same as the rest.
Matt Fisher 8/13/2022 7:00pm
8/13/2022 7:00pm
When I first put the Hinson in, it dragged a bit. It took 12 hours (I am really easy on clutches), but once broken in, it was fantastic. I used OEM springs, btw.
gscx
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gscx 8/14/2022 3:36pm
8/14/2022 3:36pm
I'm not sure if it's possible to measure on a KTM with the hydro, but there is a spec for the free play of the arm, before it starts to engage, that pushes the rod through the cases to lift up the pressure plate. My 2016 kx450 had it in the manual, after I ordered the adjustment washers to put it to the correct spec the clutch engagement was significantly better. My Honda does not have a spec in the manual and I'm not sure if other manufacturers do, just something to think about. Especially if you are changing the plate stack height from stock.

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