[subdude67]

Rebuild kits are available for the slave cylinders. Fairly routine operation. Take pictures to remind you how it all goes together. Worst part of the job is bleeding clutch fluid after slave reassembly. Keep removed slave cylinder connected to hydraulic line if possible during overhaul and keep it above height of master cylinder. This keeps some fluid in master cylinder and hose and will help keep some of the air out during slave overhaul. You will help the bleeding process by putting small amount of correct fluid in slave before installing its piston. Bleeding these clutches once they become air bound can be a real bitch. Try pre bleeding with slave held up high above master cylinder to help remove air. I use bungee cord and zip ties to hold the bastard up from the roof rafters. The air will rise to highest point and make bleeding easier. Be sure to use correct fluid in clutch master. The cover will indicate correct fluid needed.

I went ahead and ordered a slave cylinder rebuild kit last night. I could not locate one that had the piston included. Good idea on keeping it above the master!
As for what fluid to use, I looked at the manual and it states to use DOT 5.1 fluid, which I did. Then, after seeing your (and Axzon) info, there is indeed a Magura on the master cover - and it says use mineral oil........... ah beans. If it's any consolation, I'm pretty sure a lot of the 5.1 has leaked out already into the container beneath the bike (there's a small oil leak to I need to pinpoint/correct as well eventually). I'll poke around the house to see if we have any. If not a quick trip to CVS will take care of that

On older KTM's the gasket thickness between the slave and the motor is important so that the slave does not put pressure on the rod that goes to the clutch while riding. The idea is to set it so that there is a small gap between the steel ball in the slave and the rod at rest (no pressure on the steel ball in the slave).

Also, if it says "Magura" on the master lid you might need to make the push rod in the master a fraction longer to get enough stroke for the slave piston to properly open the clutch plates. And the Magura text also indicates that you need to use hydraulic oil and NOT brake fluid in the master/slave!

And fit a steel bracket/cover to the slave so that if/when the rear chain comes loose/breaks it hits the bracket/cover and not the slave... That normally also cracks the left motor half... (ask me how I know...). And as your motor casings are now obsolete the extra work is worth it...

Regarding how to get the air out of the clutch: Follow Augies suggestion and hang the slave high up. Then pump the master and open the bleed nipple on the slave. Do this a few times until no more air comes out when you open the nipple.

Yes it does say Magura. Is that a stock piece or aftermarket? I'm guessing if it is aftermarket then the push rod would need to be longer. I have no way of figuring out if the rod is stock or modified/lengthened/aftermarket. I did notice on the rod end a few (maybe 3?) washers/spacers, so there's that. But first and foremost I need to get the cylinder leak resolved, then monkey around a bit to see how far the rod travels during a lever pull.
I do have a sprocket 'guard' installed, but it's kind of beat up. I'll check out a slave cylinder cover as well.

Thank you all for the great and positive info and advice! I did go up and down the road a couple times yesterday. Shifted real good and I didn't hear anything unusual. Gonna sell one of my guitars so I can get a replacement clutch basket lol.

 

[subdude67]

Update time lol:
I got all the DOT5.1 fluid out of the cylinders/tubing. Finished off with card cleaner and a paper towel. I have a rebuild kit on order, should be here by the end of the week. Circlip pliers and a reverse bleeding system is en route as well.

Sold one of my guitars locally, so I can order a clutch basket. Do I need to order anything else along with it? I dont think there's anything on the old one to remove, but maybe there is (like some gear or plate? - are they even removable?). I didn't think to look at the original one when I had it out to file it..........blargh

Edit: Found a Wiseco in stock so I hopped on it. Also a new rear fender since the current one is zip tied to hell and back lol

 

[Axzon]

Update time lol:
I got all the DOT5.1 fluid out of the cylinders/tubing. Finished off with card cleaner and a paper towel. I have a rebuild kit on order, should be here by the end of the week. Circlip pliers and a reverse bleeding system is en route as well.

Sold one of my guitars locally, so I can order a clutch basket. Do I need to order anything else along with it? I dont think there's anything on the old one to remove, but maybe there is (like some gear or plate? - are they even removable?). I didn't think to look at the original one when I had it out to file it..........blargh

No, the clutch basket is a fully assembled unit that can not be taken apart w/o drilling out rivets. You could have left that guitar in the bedroom for a little longer. A filed clutch basket will cause no damage to the bike. And the increased rattle is minimal and hard to hear over the motor.

Looked through the thread again. Bad news is that Augie is right re you having coolant/water in the old oil, reason the motor oil is gray. Normal culprit is the water pump gasket, #15 here: 1998 KTM 125 Twin Valve Control | KTM World

Regarding the Magura components: They were fitted from the factory to earlier KTM bikes. Works well.

 

[subdude67]

No, the clutch basket is a fully assembled unit that can not be taken apart w/o drilling out rivets. You could have left that guitar in the bedroom for a little longer. A filed clutch basket will cause no damage to the bike. And the increased rattle is minimal and hard to hear over the motor.

Looked through the thread again. Bad news is that Augie is right re you having coolant/water in the old oil, reason the motor oil is gray. Normal culprit is the water pump gasket, #15 here: 1998 KTM 125 Twin Valve Control | KTM World

Regarding the Magura components: They were fitted from the factory to earlier KTM bikes. Works well.

It's all good. I still have my one electric I play occassionaly. It went to a home where it will be loved
I haven't checked the oil after my little jaunt up and down the road, but I'll be sure to do that today. That looks like an o-ring of sorts. I'll go out now and take a peek at the oil. Not sure how much riding one has to do for the oil to change but I'll find out in a few

Edit: The oil looks 'normal', but I only rode for maybe 5 mins. I was going to put it on the stand (aka cooler) and put it in gear and let it idle for 10 or 20 mins but suddenly remembered I have the master/slave cylinder drained smh. I'll order a couple of those gaskets anyhow. They're cheap, but murder you on the shipping.....yikes!

 

[subdude67]

Got the slave cylinder rebuild kit today. Installed it and used the thinnest gasket out of the 3 provided. So far so good!

 

[Axzon]

Got the slave cylinder rebuild kit today. Installed it and used the thinnest gasket out of the 3 provided. So far so good!

As the hydraulic clutch selt-adjusts the only thing you need to watch out for is that the slave, when in "home" position does not put pressure on the clutch rod. If it does the thicker gaskets come handy.

 

[subdude67]

Update:
Got the new basket in. It's a Wiseco. I didn't have a grinder to remove the rivets from the old basket - thankfully my brother in law is a mechanic with a garage full of tools
Got it all buttoned up. To see if the oil is getting cloudy due to coolant, I started it up and just let it idle for 15 mins in neutral. I should be able to check it today. Wish there was an easier way vs draining it all out to check. The original oil drain bolt was replaced by a generic bolt (and crush washer) because it appears the original was stripped out (I ordered a replacement magnetic drain bolt but found out it's too small.....sigh). Anyhow I'll check the oil soon.

Including a couple of pics (poor cell phone quality taken at crazy Batman angles lol). One represents about 12 hrs of oil leakage onto cardboard. I shoulda used a container instead shrugs
The other appears to be where the leak is coming from (water pump gasket?). If so that would tie in with Auggie and Axzons statements about the water pump seal. I ordered a couple of 'em and they came in yesterday. Gotta make sure I have coolant first (I think I have some 50/50 prestone stuff but dont know if that's usable - will do some research first). I should pressure wash it too - especially underneath where it's all crusty dirty.
Gonna visit my buddy today for a bit. Known him since first grade and he's on the last leg of a 3 year battle with pancreatic cancer. Doctors gave him a month left a couple weeks ago so I'm gonna toss back a few beers for him and reminisce on all our shenanigans and hijinks thru the years
Have a good weekend and keep the shiny side up!

 

[Axzon]

Update:
Got the new basket in. It's a Wiseco. I didn't have a grinder to remove the rivets from the old basket - thankfully my brother in law is a mechanic with a garage full of tools
Got it all buttoned up. To see if the oil is getting cloudy due to coolant, I started it up and just let it idle for 15 mins in neutral. I should be able to check it today. Wish there was an easier way vs draining it all out to check. The original oil drain bolt was replaced by a generic bolt (and crush washer) because it appears the original was stripped out (I ordered a replacement magnetic drain bolt but found out it's too small.....sigh). Anyhow I'll check the oil soon.

Including a couple of pics (poor cell phone quality taken at crazy Batman angles lol). One represents about 12 hrs of oil leakage onto cardboard. I shoulda used a container instead shrugs
The other appears to be where the leak is coming from (water pump gasket?). If so that would tie in with Auggie and Axzons statements about the water pump seal. I ordered a couple of 'em and they came in yesterday. Gotta make sure I have coolant first (I think I have some 50/50 prestone stuff but dont know if that's usable - will do some research first). I should pressure wash it too - especially underneath where it's all crusty dirty.
Gonna visit my buddy today for a bit. Known him since first grade and he's on the last leg of a 3 year battle with pancreatic cancer. Doctors gave him a month left a couple weeks ago so I'm gonna toss back a few beers for him and reminisce on all our shenanigans and hijinks thru the years
Have a good weekend and keep the shiny side up!

View attachment 109265

View attachment 109267

The oil on the cardboard looks good (thou you should really sort the oil plug so it fits properly!). You will need more than 15 minutes of idling (go racing young man!) to find out if the gray oil is from water getting in to the oil.

 

[subdude67]

Still waiting for water pump gasket. I have the o rings/seals. Need to get coolant as well. Spoke wrench came in today. I've been PB Blasting them every day for 3 days. A lot of them will turn, but the severely loose ones dont. The whole spoke turns instead . I'll prolly end up replacing some/all of them over the winter but not gonna worry about it too much right now.
Hopefully tomorrow I'll be able to drain the coolant and replace the seal/o-ring on the water pump. That may stop the oil leak. It seems to be coming right from the water pump gasket. At least all the front spokes are tight!
oh, FYI, front spokes seem to be 6mm, rear 6.8. Just in case anyone needs to know

 

[subdude67]

I…….. I think there should be a gasket here

edit: maybe not shrugs trying to find a picture somewhere to confirm/deny

2nd edit: I don’t think there’s a gasket there. The seal(s) are…….well……sealing things lol

3rd edit: I haven’t seen any oil leaking! But now coolant is dripping out ☹
Maybe there is sposed to be something between the water pump housing and the engine…..sigh. I have some black permatex. Maybe take it back off (draining the oil again) and putting some of that on the surfaces

 

[Axzon]

Here the water pump: 1998 KTM 125 Twin Valve Control | KTM World (at bottom of drawing) The seal is the big black O-ring on outside of water pump in Picture 1. (Part #75)

And here water pump cover (#52). 1998 KTM 125 Clutch Cover | KTM World

Replace O ring seals and the other seals. Also make sure all bearings are good and water pump shaft is not worn (will happen if a bearing seizes).

 

[subdude67]

Here the water pump: 1998 KTM 125 Twin Valve Control | KTM World (at bottom of drawing) The seal is the big black O-ring on outside of water pump in Picture 1. (Part #75)

And here water pump cover (#52). 1998 KTM 125 Clutch Cover | KTM World

Replace O ring seals and the other seals. Also make sure all bearings are good

yup I replaced the big O - ring #75 as well as the smaller O-ring (#21 I think it is) the bearings moved freely so I didn’t replace those. I’ll monkey some more this afternoon. I did accidentally overfill the rad, so maybe that’s it shrugs. The large O-ring was a bear to keep on the little lip before installation, but there’s no oil leaking so it seems to be installed correctly 😁. I got up this morning to check - seems to have leaked less than 1/4 cup, so maybe it’s only leaking while it’s running/warm/under pressure? Onward and upward! Gonna go to Hobo Freight for a pump up center stand as my cooler’s lid is slowly getting crushed and becoming unsteady……Zoinks!

 

[Axzon]

yup I replaced the big O - ring #75 as well as the smaller O-ring (#21 I think it is) the bearings moved freely so I didn’t replace those. I’ll monkey some more this afternoon. I did accidentally overfill the rad, so maybe that’s it shrugs. The large O-ring was a bear to keep on the little lip before installation, but there’s no oil leaking so it seems to be installed correctly 😁. I got up this morning to check - seems to have leaked less than 1/4 cup, so maybe it’s only leaking while it’s running/warm/under pressure? Onward and upward! Gonna go to Hobo Freight for a pump up center stand as my cooler’s lid is slowly getting crushed and becoming unsteady……Zoinks!

Where is the oil coming from?

If you over fill the radiator it will "adjust" the radiator fluid level by it self once motor is at operating temperature (will come out through the plastic hose that is fitted to top of radiator).

 

[subdude67]

Where is the oil coming from?

If you over fill the radiator it will "adjust" the radiator fluid level by it self once motor is at operating temperature (will come out through the plastic hose that is fitted to top of radiator).

Good to know about the coolant! I figured there was an overflow hiding somewhere. I removed most of the excess.before I put the cap on anyhow

It doesn't appear to be leaking oil at all anymore, now it's coolant
I degreased the underside and scrubbed/hosed best I can and took a few pics. I'm hesitant to tighten the bolts any further as I dont want to crack the pump cover.

Maybe I'll start it up and see if there's any difference in the flow shrugs. Gotta do something on a Friday night besides drink beer!

you can see the little drip there right in the middle. It seems to be coming from that bolt. Above it is dry, and the drain plug appears to be not leaking either. I dont remember if there is a dowel pin in that area or not, but I do know neither of them came out when I took the cover off. I've got a couple clean jugs so I can re-use my oil and coolant since they've just been put in.
Edit: I'm wondering if the pump cover is just kinda slightly pitted? It looks that way in some of the pics (there's a good pic a post or 3 above). Maybe that's why it's leaking? I wonder if I can take the cover off and run it over some 800 (or greater) grit sandpaper on a level surface to 'even it out' a skosh (sp). I would do that all the time on my computer CPU's just for fun and to bring the temps down a bit.

 

[subdude67]

Gonna see if this works.......
It seems to pop right up in Chrome and (ugh) Edge, but FF you may have to click on the big blank box..........

http://imgur.com/KVVL7vo

 

[subdude67]

A little difference! Took me like an hour lol

 

[Axzon]

A little difference! Took me like an hour lol
View attachment 109409
View attachment 109411
View attachment 109410

Nice work. Did that stop the water leak?

 

[subdude67]

Nice work. Did that stop the water leak?

Dunno yet. I put a very thin ( about 3/32” wide) bead of black permatex around the outside of the pump cover and all the way around the dowel pins, then put it on and tightened ‘er down good. Gonna let that cure/set overnight then try straight distilled water first to check for leaks. May as well make it easier on myself!

 

[Axzon]

Dunno yet. I put a very thin ( about 3/32” wide) bead of black permatex around the outside of the pump cover and all the way around the dowel pins, then put it on and tightened ‘er down good. Gonna let that cure/set overnight then try straight distilled water first to check for leaks. May as well make it easier on myself!

Wish you luck!

 

[subdude67]

Wish you luck!

I poured distilled water in and immediately heard a ‘drip drip drip’ onto the cardboard underneath lol. Looks like I’m gonna remove the permatex and try it that way 🤦‍♂️