sparky8181 Posted May 9, 2015 Report Share Posted May 9, 2015 Hi lads, Got my bike out today for first time in ages and there is a problem with the clutch, basically when I pull the leaver nothing happens. If its in gear and I pull it in the wheel is still locked, and if I have it running and knock it into gear it just goes but the clutch still doesn't work, tried going through all gears and rocking it etc to free it up but nothing. Have given it a little ride (best I can in garden) but still won't work. Any suggestions? Thanks Quote Link to comment Share on other sites More sharing options...
crazybond700 Posted May 9, 2015 Report Share Posted May 9, 2015 (edited) First check fluid level Is there ''pressure''? And does it do something or nothing at all? Cold with engine off it always sticks a bit or quite much so that does not say a lot. With engine on it could stick for a bit, but with the brakes in it should go away. Could be just sticky plates from long stand still. Edited May 9, 2015 by crazybond700 Quote Link to comment Share on other sites More sharing options...
b1gnh Posted May 9, 2015 Report Share Posted May 9, 2015 Clutch plates are stuck together strip it down and reassemble with new oil. Quote Link to comment Share on other sites More sharing options...
sparky8181 Posted May 24, 2015 Author Report Share Posted May 24, 2015 Stripped it all down today, cleaned all plates and reassembled with new oil and still doing same thing, clutch just isn't working at all when I pull the lever. Any other ideas what it could be lads? It was fine last time bike was used and had been put away for ages, now just doesn't work, seems strange. Can anyone tell me how much the piston is meant to pop out when you pull the lever? I'm wondering if it something to do with that? When I pulled to clutch lever with the clutch casing off it moved about 5mm ish, is that about right? Thanks Quote Link to comment Share on other sites More sharing options...
lineaway Posted May 24, 2015 Report Share Posted May 24, 2015 Did you measure the clutch pack or the fingers when apart? They have to be within spec, and could just be needing replaced. http://www.gasgas.com/Pages/Technical/Pro/clutch-measurements.html Quote Link to comment Share on other sites More sharing options...
sparky8181 Posted May 24, 2015 Author Report Share Posted May 24, 2015 No I never bothered measuring it as I thought the strip & clean would sort it. Surely if that was the problem it would of shown signs previously, not just gone from working perfect to not working at all? Quote Link to comment Share on other sites More sharing options...
guys Posted May 24, 2015 Report Share Posted May 24, 2015 Also thoroughly check if the clutch master cylinder isn't leaking. Quote Link to comment Share on other sites More sharing options...
sparky8181 Posted May 31, 2015 Author Report Share Posted May 31, 2015 Checked and reservoir & its full, any other ideas lads? I'm still think its something to do with the piston not pushing out enough to engage/disengage the plates, can anyone tell me how much it's supposed to move when you pull the lever? Also on gas gas Jim video about clutch pack it says that after you have removed the bolts on the casing you can remover the cover by pulling the clutch lever which inturn pushes the piston out forcing the casing apart, well when I did this nothing happened, I had to manually prise it apart to remover the casing, this is what is making me think it's some to do with that piston. Quote Link to comment Share on other sites More sharing options...
eddie1 Posted May 31, 2015 Report Share Posted May 31, 2015 Make sure that the piston in the master cylinder is fully returning. It could be that the leaver position screw is restricting it or like happened to mine the return spring had snapped and prevented the piston completing its closed stroke and therefore stopped it priming. With the cap off you should be able to see the piston moving backwards and forwards as you move the lever. If it is working correctly you will need to be careful or it will squirt liquid up. If nothing is happening something is restricting the piston or less likely the master cylinder piston seals are completely worn. If there is air in the system by tapping the lever repeatedly for a very short stroke, barely operating the piston, you should see bubbles rising up. If the hydraulics were working it would have separated the case from the engine. 1 Quote Link to comment Share on other sites More sharing options...
dadof2 Posted June 2, 2015 Report Share Posted June 2, 2015 (edited) Corrosion and "crud" build up around the back of the master cylinder piston can cause this. As the problem occurred following the bike not being used for a long time corrosion is quite likely. Check the fill port in the master cylinder is clear, you will need a very fine needle to do this. 5 mm movement sounds adequate, on rebuild you have'nt missed out somethign?, I don't want to insult your mechanical ability but anyone can make a mistake. Edited June 2, 2015 by dadof2 Quote Link to comment Share on other sites More sharing options...
sparky8181 Posted June 13, 2015 Author Report Share Posted June 13, 2015 Had another mess with it last night and found the following... Piston was stuck in, spring was ok and when I freed it up it now appears to be going in and out as it should, but still not working. Removed the cover and stuck a needle through the 2 small holes in the bottom, didn't seem blocked and with the needle in the hole I could feel the piston scraping on the needle when it moved in and out. With cover removed the is no change in fluid level when pulling lever & no squirting etc Quote Link to comment Share on other sites More sharing options...
sparky8181 Posted June 13, 2015 Author Report Share Posted June 13, 2015 if it is crud at the back of the master cylinder how do I go about cleaning it? And dadof2, you're quite right to question my mechanical ability (or lack of it lol) but the problem was there before I took anything apart, and I'm pretty sure everything went back as it should have done....or at least I didn't have any bits left over at the end :-) Quote Link to comment Share on other sites More sharing options...
sparky8181 Posted June 13, 2015 Author Report Share Posted June 13, 2015 Also forgot to mention, when I open the bleed nipple nothing comes out, even when pulling the lever maybe a tiny drop but that is it, the fluid level in the master cylinder doesn't drop, this means there's a blockage right? But where is it likely to be and how can I sort it? Quote Link to comment Share on other sites More sharing options...
baldilocks Posted June 13, 2015 Report Share Posted June 13, 2015 I recently tried to fit a used m cyl to my bike but couldn't get it to bleed. Eventually found that the bore in the cylinder was worn. Fluid didn't leak from the cylinder where the adjuster is but it wasn't building any pressure either Quote Link to comment Share on other sites More sharing options...
eddie1 Posted June 13, 2015 Report Share Posted June 13, 2015 Had another mess with it last night and found the following... Piston was stuck in, spring was ok and when I freed it up it now appears to be going in and out as it should, but still not working. Removed the cover and stuck a needle through the 2 small holes in the bottom, didn't seem blocked and with the needle in the hole I could feel the piston scraping on the needle when it moved in and out. With cover removed the is no change in fluid level when pulling lever and no squirting etc Have you pushed fluid up from the clutch cover bleed nipple to the cylinder now that the piston is fully back? When you do keep going until no more air bubbles come out. If it is still no good take the piston out of the master cylinder and inspect the seal. There is a repair kit that consists of the piston and seal but this is about 1/2 the cost of a new complete unit so a question as to which is the best option. With the top cover off and the cylinder working it should definitely squirt up if it is working correctly. Good luck Quote Link to comment Share on other sites More sharing options...
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