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ollys

Clutch Rebuild On Txtpro 200

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Im going to be attempting a clutch rebuild on my TxtPro200 as it has a heavy action, and hopefully this will rectufy it. Any advice for things I should look out for as I haven't done this before?

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Just spoke to the guy who had it before me, and he said he did a full rebuild on it before I bought it. His explanation of the heavy clutch was 'you just get that with some models'.

Its an '05 Pro model, so I thought the clutch would have been featherlight. His only suggestion was to put a bigger master cylinder on it like one off a GG Enduro bike to get a lighter feeling clutch. Has anybody heard of this or had experience doing it?

Id rather not needlessly rebuild my whole clutch if I can get a lighter feel just by replacing the master cylinder.

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Id try bleeding it to make sure there isnt any air at all, if there is the slightest bit it can make a huge different,

also my clutch differs when i use different oil! I use realy thin stuff and if you use thick oil it can make it heavy or really drag! Only thing is the clutch rattle is louder with thin oil, does no harm though.

I now use dextron 3 which can be made by any oil company, its a transmition fluid for automatics, halfords own is very cheap and also its made by motul apparently,

Id try these as they take less time and cost less before you pull it apart!

Gav

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Hello Olly,

Usually, a heavy clutch on a PRO motor is indicative of the plates swelling - usually by contamination with water or incorrect gearbox oil. If the clutch pack height is correct, and more importantly, the clutch basket lever height is within tolerance then this department is ok. Only other problem I have found is the clutch hose being nipped causing a restriction in the ID of the hose. Have a look under the tank around the headstock area.

Bye, PeterB.

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Ta PeterB, more things to look out for. Just replaced the pump in the master cylinder (rubber gasket was ripped and adrift) so i can cross that off the list. Bled it through thoroughly, defo no air in there and it still feels pretty much the same (although maybe slightly better but just might be me imagining things). Il check the hose also.

The guy who had it before me had been running it on Dexron 2 ATF, probably for quite a while however he put new clutch plates and 'seals' in before he sold it to me. Could this be a cause of the clutch plates swelling as it is of a less dense consistency than 10w40 proper oil, and would it have happened that quickly? He also said to only put 400cc's in each oil change (after every session I ride), and in the manual I found online for an '04 model it said 550cc's of 10w40. My thoughts as to why only 400cc's of ATF is that it will expand mor than 10w40, is this correct?

I think after next sundays trial it may be time to fully take the clutch apart, measure tolerances etc.

P.S It drags quite a lot too unless I have the lever right into the handle bars. Is this also a sign of clutch plates swelling?

Edited by OllyS

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If he put in the new style clutch pack the plates could have been installed incorrectly. You need to measure the thickness of the clutch plates, the thickest one goes in first. The 2 remaining plates should be the same thickness. All the new clutch packs we get in the US are this way

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^^^ 'Factory Kev' said that his first thought was that the clutch had been installed incorrectly. Will check it out after the weekend.

Ta for the info chaps :rolleyes:

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Got a bit of a noobish problem . . .

Took the clutch housing off last night, and wasnt sure whether to take the clutch plate setup apart due to the GG star shaped nuts (I only had a molegrip to do this, is it ok if I use those? Is there a special tool?)

So I opted for not doing it, however whilst there I replaced the 2 O-rings under the top hat thing as a couple of people said that might have been the problem. Put the clutch housing back on with a new gasket etc, all did up fine but when it came to bleeding the clutch through I couldnt get rid of te air in it. Spent near on 1.5 hours trying to no avail. Even when I took the top off the slave cylinder completely to try and get fluid through from the master, it was only coming through in small drips and just blowing air through. This seems odd, and the level in the master cylinder would not go down at all. Tried reverse bleeding it, with syringe on the slave and trying to push the fluid up through the system, but that would not work. The syringe wouldnt let me pump any in at all, even with the bleed nipple wound quite far out also.

What have I done wrong!? Would it be something to do with how I put the top hat/actuator pin back together? Help . . . .

Something else I noticed whilst dabbling was that the clutch release springs (I think - metal prong shaped things pointing in in a circle) had a bit of wear on the top 3-4 but no wear on the bottom. Also, one of them seemed stiff. Could this have been a cause of the heavy clutch?

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Got a bit of a noobish problem . . .

Took the clutch housing off last night, and wasnt sure whether to take the clutch plate setup apart due to the GG star shaped nuts (I only had a molegrip to do this, is it ok if I use those? Is there a special tool?)

So I opted for not doing it, however whilst there I replaced the 2 O-rings under the top hat thing as a couple of people said that might have been the problem. Put the clutch housing back on with a new gasket etc, all did up fine but when it came to bleeding the clutch through I couldnt get rid of te air in it. Spent near on 1.5 hours trying to no avail. Even when I took the top off the slave cylinder completely to try and get fluid through from the master, it was only coming through in small drips and just blowing air through. This seems odd, and the level in the master cylinder would not go down at all. Tried reverse bleeding it, with syringe on the slave and trying to push the fluid up through the system, but that would not work. The syringe wouldnt let me pump any in at all, even with the bleed nipple wound quite far out also.

What have I done wrong!? Would it be something to do with how I put the top hat/actuator pin back together? Help . . . .

Something else I noticed whilst dabbling was that the clutch release springs (I think - metal prong shaped things pointing in in a circle) had a bit of wear on the top 3-4 but no wear on the bottom. Also, one of them seemed stiff. Could this have been a cause of the heavy clutch?

If it's the first time you've seen a Pro clutch, they can be a little scarey. The screws are 7mm 12-point and although GasGas has a special socket, you'll be able to find a "7mm, 12-point socket" at any good tool supply store.

"and the level in the master cylinder would not go down at all"-this usually is a result of the adjustment screw on the lever turned in too far. Make sure that there is a little gap (maybe .01", just so you can feel it) where the lever adjustment screw meets the plunger rod that passes through the rubber boot to the M/C piston. Reverse bleeding usually is not necessary with a clutch on a Pro. There is a possibility you didn't fill the lower servo cylinder (looks like old President Lincoln's stovepipe hat, so it's sometimes referred to as a "top hat") with brake fluid before installing it on the post on the sidecover and there is some air trapped there. Usually it works itself out but sometimes, as a last resort, you may have to take the sidecover off, turn it "upside down" (servo cylinder hanging down) and pump it to clear the air up into the fitting. It does not take much air to get a spongy feel as the 9.5mm bore in the M/C does not displace much fluid.

Check the adjustment screw clearance first. I've generally found that the two main causes of a "heavy" clutch are (1) clutch pack too thick (should measure about 17.5mm from top of hub bore to fingers) and (2) swollen o-ring(s) on the top hat post on the sidecover.

"clutch release springs (I think - metal prong shaped things pointing in in a circle) had a bit of wear on the top 3-4 but no wear on the bottom"-you probably mean the fork-like "fingers", which will have a "line" at the top (wide part) where they move on the pressure plate, which is normal. "Also, one of them seemed stiff" not quite sure what that means, but maybe it somehow got bent? I've never heard of that happening but there's always a first time. I always like to assemble the clutch with the bike on it's side and before tightening the clutch plate screws, pull up on all of them to be sure they are "free" and everything is "centered" before tightening the pressure plate down.

Check that lever adjustment screw clearance first and let us know if it makes any difference.

Cheers

Jon

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Hi Olly,

Just a small point, what year is your 200?

From 2005 onwards, the PRO uses mineral oil in the clutch actuation system, not hydraulic oil (DOT 5 for example) - just so you didn't add to your current problem, which I still think is related to the clutch pack height, as advised by Jon. When looking down into the clutch, the lever fingers should angle upwards/outwards more so than resting in the horizontal plane. They act like a kids see-saw except the pivot point is a central ring. If the levers are showing to be angled outward, then they have a good mechanical advantage and will provide an easy to use clutch actuation.

Bye, PeterB.

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Hi, yeah its 2005, I am using LHM Mineral oil (from the GG supplier) The teeth seem fairly well angled out, my only concerns with those was that the small ends on the top 3 seemed like they had a bit of scoring and one lower left one felt like it wasnt moving very freely.

Off to try and get a 7mm star shaped socket so I can properly take it apart now . . . . . . .

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Hi

I have been following this informative forum with interest.

I have a similar problem with the clutch of a Gas Gas pro 2005 dragging.

The clutch dis-engages drive when the lever is pulled 1/2 way in but continues to drag all the way into the handlebars. Cant change it into neutral and sometimes it stalls the engine if left idling long enough.

I have bled the clutch line, I use Motul transoil, checked the free play of the lever, etc

I took the side cover off and measured the plates thickness whick was OK.

I then checked the fork fingers and most of them are at the correct height about 17.5mm

There are a couple that are at 16.6mm though and a couple that were not moving freely when I first removed the clutch. There freed up after I operated them a few times.

Is it important that the fork fingers be all at the same height? If so what is the best way to adjust them?

Ian

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