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Newb bought a pair of older 280's - need some guidance!

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First post here, hoping you guys can provide some guidance.  I just picked up a 2001 TXT 280 and a 2002 TXT 280 Edition (from the same seller) and need some help.  Does anyone have the owners manuals or a way to obtain them?  Same thing with the service manual.  I need to change fork seals and would like oil height, torque specs, etc.

Also, are there any things I should be looking for on these machines?  They've been loved, but are in workable condition.

Lastly, how much rotor float should there be on these bikes?  Both bikes' front rotors are loose.  Bolts are tight, but there is a large amount of axial and rotational slop.  I don't know if the bushings are worn, if the rotors are past their prime, or both.  Or if this is just normal.  Hopefully a service manual will shed light on some of these questions.

20170709_201802.jpg

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You can download an parts manual from the GasGas website:

http://www.gasgasmotos.es/us/manuals/models-1-2001.html

but no owners manual I'm afraid.

The brake discs (rotors) are floating so there should be some movement.  I think the older bikes tend to have more float.  There are washers that hold the disc on but allow float, as long as these aren't bent, the float should all be normal.

Cheers

Wayne.

Edited by waynerobshaw

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Thanks for the responses, guys.  I did find that link to the Gas Gas site the other night and the parts diagrams were very helpful.  Bummer on the owners manuals, though.  I'd like some of the simple information such as fuel/oil ratio...the owner was running 40:1, but I've 'heard' that these need MUCH less oil.  I literally know nothing about these things...other than I can have a blast in my backyard for over an hour!

I'll check out that YouTube link, thanks!

Back on the brakes, though.  How good are the front brakes supposed to be?  I get a really good squeak out of it and it doesn't bite anywhere near as hard as I'm used to.  Even my lousy old KTM has a better front brake.  I guess I expected a stronger brake on a trials bike to loft the rear wheel.  Something like the rear brake which works AMAZING.  Hopefully just a matter of a fresh bleed and new pads(?).

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The brake rotors are “floating” type which means they can move some, but they should not rattle. Pop off a couple screws (or all if you want) and put a dab of silicone glue on the tabs, then reinstall the screws.     

 

The squeaking can usually be eliminated with a little deglazing of the rotor and pads with some 280-220 emery cloth.  New pads are pretty inexpensive if they are badly worn or too thin. 

 

Bleed the brakes well with new fluid.  Rebuild kits for the master cylinder are also pretty inexpensive.  I thought my brakes were OK but after rebuilding and bleeding I was pleasantly surprised at how much better they worked. 

 

Compare the size of the rotor on your KTM to the Gassers.  Probably a lot bigger diameter on the KTM.  You don’t need massive braking on a trials bike, you need to learn proper body position and techniques.  Watch some good riders who can hop their rear wheel when completely stopped.  That is not about brakes, that is technique. 

 

Enjoy your bikes. 

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Most people run about 80:1 fuel:oil ratio.  Reducing the oil will result in a richer mixture so you may need to adjust your idle screw a little. 

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23 minutes ago, thats_a_five said:

The brake rotors are “floating” type which means they can move some, but they should not rattle. Pop off a couple screws (or all if you want) and put a dab of silicone glue on the tabs, then reinstall the screws.     

The squeaking can usually be eliminated with a little deglazing of the rotor and pads with some 280-220 emery cloth.  New pads are pretty inexpensive if they are badly worn or too thin. 

Bleed the brakes well with new fluid.  Rebuild kits for the master cylinder are also pretty inexpensive.  I thought my brakes were OK but after rebuilding and bleeding I was pleasantly surprised at how much better they worked. 

Compare the size of the rotor on your KTM to the Gassers.  Probably a lot bigger diameter on the KTM.  You don’t need massive braking on a trials bike, you need to learn proper body position and techniques.  Watch some good riders who can hop their rear wheel when completely stopped.  That is not about brakes, that is technique. 

Enjoy your bikes. 

 

I figured they'd float, I just didn't know how much was allowable.  It gave me pause when I squeezed the front brake lever and bounced the forks.  Lo and behold, I found a definite click when the entire rotor would rotate about the mounting bushings/screws.  It was a weird sensation that I've never experienced before on any of my other bikes (many other current and former dirt, street, and track bikes).

I'm going to do a good once over and figured I'd do what you recommended.  I think I'll also rebuild the m/c since it IS going on 16 years old!

My allusion to my KTM was mainly that its brake was/is amongst the worst I've experienced on a dirt bike.  I've learned to live with that, but it's just not as reliably good as others.  Another topic for another day.

I'm looking forward to learning, thanks!

20 minutes ago, thats_a_five said:

Most people run about 80:1 fuel:oil ratio.  Reducing the oil will result in a richer mixture so you may need to adjust your idle screw a little. 

OK, that confirms it.  I was told 75:1.  It didn't sound crazy to me given the engine speeds these things typically run, but I wanted to verify before doing permanent damage!

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Trials motors don't need the frequent top ends like MX'ers.  Many trials bikes go for hundreds of hours without rebuilds.  They are so lightly stressed compared to bikes that are constantly on the rev limiter.  Those TXT's are almost bulletproof in that regard. 

 

Do keep your eye on the tranny fluid.  The water pump seals have a tendency to go out, resulting in milky oil.  There are kits with the seal and a new shaft because they get grooved.   Keep good grease in your linkage (dogbone) bearings and always carry a spare plug. 

If you do any long uphills, expect the accumulated oil in the exhaust to smoke quite a bit.  Its normal. 

Lots of good videos on Youtube.  Watch them on slow speed to be able to see the techniques more easily. 

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There's no spooge on the exhaust now, but I'm used to it with my KTM.  This bike is clean in comparison!

I just got off the phone with Trials Parts USA looking for some parts.  He more or less said the same things regarding the water pump and engine in general.  I'll be doing a thorough once over on these bikes and will probably do a light duty resto on them this winter to make them fresher.  I was excited to buy a trials bike, but I'm giddy now that I've ridden my own, lol.

He did mention that it sounds like my brakes are in need of service.  New caliper and maybe a m/c rebuild.  Time to start looking for calipers...

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Normally there is no need to replace a caliper. A rebuild kit with o-rings and pucks if you were to be thorough.

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His perspective was that the seals aren't currently available and that the calipers weren't very good anyway.  I have no dog in this fight...

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I have a line on an AJP.  I think I'll bite the bullet.  Any good source for AJP parts (seals)?  May as well refresh it while it's off.

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Thanks for the heads up.  Gas Gas got back to me with the same news a few weeks ago and I neglected to update the thread here.  Feeling pretty happy to have this before really tearing into anything.

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hey OP if you re still tuned in can you tell me what you ended up doing about your brakes? Did you go with braktec calipers?

thanks!

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So far...nothing.  One of my bikes is usable, though not ideal with the front brake.  I've been working on so many other projects that I just haven't had time to address it.  However, I plan to find some time to go over the bike very soon.  Just picked a new set of tires last week, so I'll get to it soon.  

braktec, ajp, whatever I can find a deal on.  I have a feeling the seals are starting to seize in my Hebos and that what the issue is.  Just a guess though...

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