Severe clutch problem EC 300 2019

[Doc Brown]

After I had squealing/juddering problems I replaced the friction and steel plates plus I installed a Rekluse basket, the same that is used on the 2018 GP models.
While the squealing is gone another problem appeared and is getting worse.

My bike always had a slight clutch drag which didn't change with the new clutch. Today, after riding about 25 minutes I took a rest in the shadow for about 2 minutes. Started the bike and when I put first (or second) gear in it immediately leaped forward and died. I then tried to re-start it in gear but it immediately wanted to roll away and died. I tried this about ten times but no joy. Then let it idle for about a minute and whacked the throttle a few times the problem was gone.

It did that several times but I was unable to find out why. It did it with the engine warm, cold and hot. It was worst when I shut off the engine for a minute or two. It would not do it when the engine stalled and I immediately started it (in gear). As I had an identical bike at hand I found some differences.

On my bike the clutch pull is definitely lighter as on my friends bike.

When on both bikes the clutch levers are adjusted as far as possible from the bars and I pull the lever fully in, I can release the lever a tad more than half an inch on my friends bike and nothing happens but on mine it would almost immediately leap forward when releasing the lever just a hair from the bars...

So I think his slave cylinder moves the pushrod further than mine, the question is why.
I bled the system twice. First time as usual, second time with slave off the bike and piston fully pushed back. But nothing changed

What is confusing me is the parts fiche that shows the slave cylinder AND an o-ring with part number ME25632024. Where should that o-ring sit?

I also saw one drop of hydraulic oil coming from the gap between piston and cylinder when I pushed the piston fully back, but it seems the system does not lose oil. When I had the slave off I did not see an o-ring like in the parts fiche but I saw a black, flat rubber (?) between piston and cylinder.

I am stumped, so ordered a new slave for testing.

Any ideas?

 

[Jacob 'Berg]

Is this the first ride on the new clutch pack and basket?

Were all steel clutch plates installed facing the correct direction?

Worn shaft end?

Slave may have a small leak and may not leak enough to notice, but may pulling air into the system. Or, maybe you just need to bleed the system again.

 

[Gasser Nate]

It 100% sounds like it has not been bled properly. The lighter lever plus releasing as soon as it is off the bars points at this. New plates always drag when new. They need bedding in just like brake pads and discs. Bleed the system again, you can try reverse bleeding and give the clutch a few good hard slips and it will probably come good.

 

[Doc Brown]

@Jacob:

No, I already rode the bike for 3 hours in easy terrain last week. There wasn't much clutch slipping necessary. Yesterday the terrain was a bit harder and I rode the bike 3 hours again, so in total the clutch is 6 hrs old. It was darn hot (about 94 F).

I called GG in Germany and asked them how to install the steel plates and they said it plays no role as long as they all face either outwards or inwards (with the sharp edge).

Shaft is good, checked both ends.

There is no leak visible, fluid level in the reservoir did not change, at least it isn't visible. But yes, it is possible that there is a leak letting air in.
I will bleed it again while waiting for the new slave.

Yesterday, when the bike always stalled when I put it in gear, I pumped the lever about 20 times and tried again, but that didn't change anything. (That worked on my KTM when air was in the system.)

@Gasser Nate:
I even bled it with the slave off the bike and the piston pushed back, that normally eliminates air that you wont get out during normal bleeding process. However, I too have the feeling the problem is related to the hydraulic part of the whole system (slave or master cylinder).

Will bleed again and report back but may take a few days.

Thank you both for your help, really appreciate that.

Doc

 

[RudolfHucker]

The easiest way to check the steel plates for direction is to let them drop down the splines in an empty basket. They should drop straight down but will hang up if the splines have been cut in such a way as to be directional.

The 1st KTM I ever had had terrible clutch drag from new and this was the issue. They had been thrown in at the factory and most had been put in the wrong way round.

 

[Neil E.]

So what is the preferred direction? Sharp edge inward or sharp edge outward?

 

[Greatdane]

I have heard the magura slave cylinder seals are prone to fail. Happens on new husky s too. From what I understand the replacement seal kit from a brembo (ktm) unit will work and is better quality.

 

[Jacob 'Berg]

So what is the preferred direction? Sharp edge inward or sharp edge outward?

Someone correct me if I'm wrong, but I mount them with square edge towards the pressure plate (out). Chamfered edge in. Probably the most important, as others have stated, is having all of the steel plates facing the same direction.

 

[RudolfHucker]

Usually, the sharp edge is slightly bent down by the pressure of the cutting out process. Again, this can be confirmed by the method I described earlier

 

[Doc Brown]

Someone correct me if I'm wrong, but I mount them with square edge towards the pressure plate (out). Chamfered edge in. Probably the most important, as others have stated, is having all of the steel plates facing the same direction.

My friend said we did it that way, I admit I can't remember.

Today we bled the system again the normal way. There was no air visible in the bleeder hose. We then reverse bled the system using a big syringe and a very tight fitting rubber hose.
I was surprised how much force was necessary to get the fluid pumped up to the reservoir. And yes I had the bleeder nipple opened far enough.

The feel on the lever did not change. The test ride showed that nothing has changed. With the engine cold it drags quite a bit but that is something that does not bother me too much. I then warmed the engine up going up and down the road. I also feathered the clutch a few times to get some heat in it.

With the engine warm I can put it in first or second gear, no drag. I also could start it in gear. Then I shut the engine off and gave it about 1 minute before I re-started it. Bingo! I put it in gear and the drag is so bad that it immediately dies. Starting it in gear is not possible, it drags so bad that it leaps forward with every revolution of the starter motor.

I can reproduce that as often as I want. As soon as I give the engine a rest and re-start it, the problem is there. If I leave it running all is good.

In desperation I took off the slave cylinder but didn't find anything unusual. But I now know where the o-ring the spare parts fiche shows sits and what it does. It's just there to avoid engine oil making its way through the cylinder. The oil I found on the piston is gear oil that comes from the push rod and a bearing.

Two things I noticed seem to be unusual. When I pull the clutch with engine off, I can hear a sucking noise from the clutch side. Hard to describe its a knocking noise as well. I remember that my KTM made a similar noise.

I changed my handle bars later on so took of the clutch master cylinder and let it hang down. When I mounted it to the new bar the clutch pull was considerably firmer than before. But before I could test ride it, it went back to how it was before. Furiously I bled the system again both ways (normal and reverse) but nothing changed.

I have a new slave cylinder on order but I fear it wont change anything


edit: gear oil is 10/50 Amsoil dirtbike oil. Oil level is slightly over the maximum but a small air bubble is visible on top of the sight glass...

 

[rvangeel]

Perhaps the master is not working correctly? Maybe bypassing some fluid so you aren’t getting full pressure?



Sent from my iPhone using Tapatalk

 

[Jacob 'Berg]

This may be a bit of a pain, but it will eliminate the slave and master as a root cause. Pull the whole slave/master/clutch lever from your buddies bike, bleed it well if needed, and put it on your bike.

If you are still getting the same symptoms, you know it is downstream from the slave cylinder and is likely rooted in the clutch pack assembly.

 

[Doc Brown]

Yes, I will wait till I get the new slave, install it, then test, when nothing changes I will take my buddies master cylinder.

I will report back. In the meantime many thanks guys, your help is much appreciated!

 

[Doc Brown]

I have heard the magura slave cylinder seals are prone to fail. Happens on new husky s too. From what I understand the replacement seal kit from a brembo (ktm) unit will work and is better quality.

Are you sure that the Brembo prts will fit into the Magura cylinder and the seals will work with hydraulic oil?
Do you know which KTM/model year?

 

[Doc Brown]

Update:

Today I disassembled the clutch master cylinder, cleaned it with brake cleaner and pressurized air, then oiled it with hydraulic oil and installed an OEM repair kit. The original parts looked mint so I did not expect the repair kit to change anything. I just took it as my dealer had one on the shelf. I reverse bled the system.

Test ride, but nothing changed, everything the same as before. When hot engine is stopped for longer than 30 seconds I cant start it in gear or if I put it in gear it instantly dies.

In the meantime I am convinced it's the clutch and it has nothing to do with its actuation system. I will however, install the new slave as soon as it arrives but I really doubt it will change anything.

After the frustrating recognition that whatever I did to the hydraulic system has no effect I changed the gear oil and found, that I had filled 900cc, which is 100cc too much. The manual states that oil level has to be between min and max dots on the sight glass. (see attached screen shots) And after refilling 800cc and letting the engine warm up and cool down, the level is exactly at the maximum mark.

The test ride showed that with less and thinner oil it was considerably better, but far from perfect. My theory, when the engine is shut off all oil returns at the bottom of the engine and causes the drag.
What I don't understand is why the problem did not appear the first 3 hours of (light) use without clutch slipping. It started after about 4 hours. Maybe the clutch friction plates have swollen up or they need some abuse.

So all I will do is ride the fucking thing and see what happens. Enough time and money wasted...

 

[Jacob 'Berg]

I would pull the clutch pack and take a look at the friction plates and steels. Maybe one of the steel plates are in the wrong direction, or possibly something was out of spec from the factory. Does not take long or cost anything.

 

[Doc Brown]

One problem is gone another one is back

I changed the oil again and this time used thinner 10/30 gear oil (Motul).

After a longer ride yesterday the dragging problem is completely gone, except when the engine is stone cold. I really can live with that.

Unfortunately the squealing is back even when the clutch is only slightly abused. So I invested in a new Rekluse clutch basket, new steel and friction plates, a new slave cylinder plus a repair kit for the master, new oil all together for USD 590.- where I live and still no joy.

I think the time has come for the GasGas and I am sad as it was a brilliant bike but I have reached the point.....

 

[Gasser Nate]

Sounds like you just need to find a compatible oil mate. I would not be throwing the towel in just yet.

 

[Doc Brown]

Sounds like you just need to find a compatible oil mate. I would not be throwing the towel in just yet.

I pray you are right, I'll try a different oil.

 

[Gasser Nate]

Don?t be afraid to try motorcycle engine oil too. It does the same job of lubricating the gears and the clutch. Often you can get a good quality synthetic oil in bulk for a lot cheaper.