Gasgas clutch drag with new clutch. jtr250

[betabell]

I purchased a Gasgas jtr 250 towards the end of last year and have not used the bike much. I have changed the oil four times and it’s always come out a strange grey colour. I have also been having clutch dragging issues. I have used different bands of oil but this has not made any difference to the dragging. The dragging seems to happen more when the bike has warmed up a bit. If I pull the clutch in and walk the bike back a bit a step or two this makes the bike want to move forward even more.  The master cylinder was probably the original one and in trying to remove it to clean one of the bolts snapped off. I purchased a new AJP master cylinder which I fitted. I then removed the slave cylinder, it looks as though there may have been a small leak so I purchased a rebuild kit and fitted. This made no difference. I then removed the clutch plates the basket which looked ok with no significant groves or anything. The metal plates were a little rusty but I am not sure how much use it got by the last owner as it was more a spare back up bike. One of the friction plate had some delamination of the friction material. I have fitted a new surflex clutch pack with new Gasgas springs as well. I have also fitted a new upgraded Gasgas water pump kit with bearings shaft and seal etc. I have just put the new clutch in today and got everything back together and there seems to be no difference. Clearly there have been issues with clutch plate delamination and slave cylinder seals but rectifying these does not seem to be making and difference. I quite like working on the bike but would like to see some progress. I am not sure if this is as good as it gets or if there is something else I should try.

 

Here is a list of the oils I have tried

With the old clutch in

 

Wilko semi synthetic 10w40 - very cheap I just wanted to use this as flushing oil and I changed it very quickly

MTL Fluid Extra Light 75wt

Putoline light gear oil 75w

 

With the new clutch pack in

Motul Transoil 10w30

I have seen a Jim Snell video and he says to use 5w30 mineral engine oil but I can’t seem to find any in the UK.

I have seen some Pennzoil 5w30 mineral oil on eBay but it says that it cleans up to 40% of engine sludge in the first oil change?!~  -  I was not sure if this would be suitable for a motorcycle with a wet clutch. As I say any help or advice would be greatly appreciated.

Kind Regards James 

[peterb]

Hi James, quite a few issues there.

The hydraulic clutch system on the older GG's are synthetic DOT 4, was the AJP master cylinder that you bought kitted out for mineral oil or for DOT 4, ie: does it have a black or green cap.

What type of hydraulic oil did you use to fill the actuating system. You need DOT 4.

The slave kit that you replaced, did this include a piston with seals.  Sometimes the ball bearing from an old piston is pushed back into the piston and does not allow the slave piston to fully dis-engage the clutch. Did you fit the slave piston return spring.

As oni asked, is the clutch pushrod ball bearing in place, it can be easily left out.

For years and years on the older GG motors, we always used ATF rated to Dexron III, it's low cost, works well and does not create any clutch drag. 600ml is fine on these engines. Bye, Peter B.

[d2w]

Hello,

I don't have direct experience with your model of bike, but I found that the clutch drag on my 2008 GG TXT300 was particularly sensitive to the clutch lever freeplay (or lack there of). On one ride in particular the clutch progressively "slipped" as the system heated; a quick back-off of the clutch free-play adjustment screw restored my clutch operation. So I suggest you check your clutch master cylinder for correct and full operation.

And in reading your above post it seems odd to me that you would find rust on the clutch plates. Perhaps the water pump seal was leaking and that would also contribute to the grey (milky (?)) oil you found? Could something else in the clutch mechanism be rusty and its correct operation compromised?

Dale