thats_a_five

The first thing I suggest is make sure your current bike is giving you all it can. Clean the air filter, replace the plug, de-coke the head, the pipe, de-gunk the silencer and repack it. Make sure your throttle cable is giving full opening of the carb, and get the fetting right. If you want more, check the squish height of the head and adjust it to the minimum spec by changing the base gasket to increase the compression a little. I am not sure if your bike has a flywheel weight and research if removing it is a good idea. I tend to avoid making significant power upgrades to equipment because the rest of the bike was designed to work with that motor. The clutch, transmission, chain etc may be overstressed ( I am not sure if these items are the same or lighter design than a 250 or 280). The kit to upgrade the cylinder may be OK but I agree with Tankygsy that people will not pay more for a bike with it. One good thing about staying on a lower power bike longer is that it will force you to maximize your skill and technique with it. Ride it and advertise that it is for sale. You will eventually find a good buyer and can upgrade to a more powerful bike and be an even better rider. Whatever you do - get out and RIDE!

When you take the thermostat out, take a close look at the rubber grommet that it presses into. Mine split and the flange started coming off while out riding one day. The flange is the only thing that holds the retaining clip in place so you can imagine that the 'stat came out and dumped all my coolant. Not a good way to start the day. I was able to make a field fix by sacrificing a plastic bag and tie wrapping the stat in place so was able to finish the day with only a slow leak. Thankfully I wear a hydration pack and could refill the radiator about every 4 sections. Oh the things we do to keep riding!

16 Pounds for an oil seal? I bought mine for US$3 It was 15mm x 26mm x 7mm thick. Yours may be different so I would remove it and take it with you. A quick google search found this source in Liverpool. http://www.hesliverpool.co.uk/Seals.html Pretty likely they will have it and also other seals and bearings you might need. Thanks to Jon for adding 2 more ways that water can get in the gearbox. He is the master. While you are stripping the bike down, be sure to check the bearings in the rear suspension - especially the dogbones. They get lots of dirt and water on and in them. Bearings are cheap. Replacement dogbones are spendy. Cheers.

Milk is not usually recommended as a lubricant! MIlky oil will cause lots of clutch drag. Water can get into the gearbox 3 ways: 1) Bad water pump seal (most likely). 2) bad o-rings between head and cylinder. 3) Leak from water jacket in the cylinder (unlikely but possible). I took out my old water pump oil seal and went to a local bearing and seal shop and bought one. BTW, pry out the oil seal, don't drive a screw through it as a "handle" like some people recommend. There is a bearing right behind it that can get damaged if the screw goes in too far. There is a temperature switch in the radiator hose that turns the fan on when hot. If you want to test the fan, simply unplug the 2 wires from the temp switch and connect them together. Start the bike and the fan should come on. With water in the oil, the clutch will drag badly, making it harder to shift. Check that the gear lever is not bent against the left side cover and dragging. Some people have complained that Gassers have weak transmissions. A friend who is a US champ told me that he stopped trying to move big rocks with his shift lever and he has no trouble with transmissions anymore.

Based on the pics, I would say it is a 2000 TXT280 "Edition" model. Notice the 2000 on both sides by the seat and even the stator cover. On both sides of the tank cover it shows 280. GasGasMuseum.com shows this configuration of bike and plastics, but in red, not blue. It seems that different colors were available in different markets. It is definitely not the "Pro" version but the earlier "Edition" design. The "Pro" came out in 2002 while the "Edition" model was offered from 2000 to 2002. The only way to know for sure is to get a VIN. I have seen threads with the decoding scheme listed on here before. I am a bit of a skeptic sometimes and when I see 2" and 3" numbers on the side of a bike that do not match the decription in the ad, it makes me wonder.......

Craig, Welcome to trials riding. Here are some trials tips from an ex-enduro rider. 1) Keep your knees out wide. Don't try to hug the bike like in enduro and MX. 2) Keep your head out on turns. As soon as you move your head to the inside, you will dab. 3) More throttle is NOT the answer to all problems. More throttle CONTROL is the answer. 4) Don't be in a hurry to jump to a more powerful bike. Unless you are attacking really big obstacles, you do not need huge power. The lower power bike will force you to learn the technques better. 5) Most importantly, have fun! The older TXT's seem to work best with ATF in the gearbox. The clutches all seem to drag a little, even with new oil. WHen you drain the oil, check to see if it is just dirty or if it is milky. If milky, the seal in the water pump is leaking. Water in the oil will make the clutch drag lke crazy. Also, antifreeze will eventually dissolve the glue that holds the fiber plates to the clutch disks - the clutch then works like an on-off lever with lots of drag.

My bike is older and not a "Pro" so the springs are different. I am not an expert on the pro. You may have to remove the clutch basket to see the rollers on the gear selector drum. They are spring loaded and have a lot of tension to keep the drum from turning and holding the bike in gear. Check that they are working correctly and not binding up. Check your radiator for oil in the coolant also. If you find any, change the water pump seal beforre you put in the new clutch pack. Water in the oil will make the clutch drag like crazy and potentially foul the new clutch material. With the clutch off you should be able to turn either the rear tire or transmission shaft and select all the gears with the shift pedal. That should tell you if there is a problem inside the gearbox or just under the clutch cover.

"...i do plan on using the bike when i get anougther towbar fitted." Are you planning to put a tow bar on your Gasser? LOL. What next? Mirrors and cruise control? Cheers.

It is quite common for trials bikes to be difficult to shift into neutral. That is a good thing. You do not want it finding neutral when you don't want it to. Have you changed your gearbox oil? I have found that to be the first thing to do when my clutch begins to drag. Look at the fluid you drain. Just dirty or milky, metal parts, etc? Under the clutch, check the springs on the gear selector rollers. They should be pretty firm. Also check the shift adjustment per the Jim Snell video.

The rose bearing can be replaced. It is a little difficult to describe without pictures but here goes. What looks like a large bushing that you put the bolt through is actually made up of a rose bearing, 2 turned bushings and 2 o-rings. The rose bearing is pressed into the eye end of the shock. Then bushings are pressed into the ID of the rose bushing from both sides. These 2 bushings extend out each side of the eye. The bolt actually goes through these bushings, not the ID of the rose bushing. Each of these bushings has an o-ring to keep the lube in the rose and keep the dirt out. If you are clever with a bearing press or large bench vice you can press the assembly out and replace just the rose bearing and o-rings. If you need a quick, temporary fix you can clamp one bushing in the vice, grab the other with a big pair of vice grips, twist and pull the bushings out. Then force some thick grease into the rose and reassemble. The grease will reduce the play in the rose for a while, but if there is play in the rose it should really be replaced. I was able to get replacement rose bushings from a local bearing shop here in the US. I needed to take out the old one to measure and get the right size. Good luck. And keep the feet up!

I have a 94 JT25 and I have found the best oil to use is ATF. When my clutch starts to drag I simply change the oil and it is fixed. If you have oil in the radiator or water in the oil, the water pump seal is the most likely culprit. The water pump is located on the right side of the engine. Follow the water hoses down from the bottom of the radiator and there it is. You can unscrew the 2 bolts and the water pump comes right off. The seal is an easy job once you get the old one out. Try to pry it out rather than to drive a screw through it to pull it out. The bearing is right behind the seal and if you drive a screw in, you can damage the bearing cage and then you have to pull the whole clutch side cover off (guess how I know). There is not a workshop manual but there are many you tube videos made by Jim Snell than cover many of the maintenance items such as this.

It sounds like a fuel issue to me. Try kicking it a few times then pull the spark plug. If it is dry a thorough cleaning and blowing through all the passages in the carb (especially the choke and main jets) should do the job. If it is wet, clean the plug, remove the air filter, kick it to clear the jug and bottom end out, reinstall the plug and try again. It may be as simple as a plugged air filter. Replace the plug even if it looks good. De-coking the exhaust will not make it start better unless it is clogged to the point where it cannot breathe at all (unlikely). There are other threads with onfo about ways to do this. Let us know what you find.

Acerbis makes 2 sizes of tanks that munt on the upper part of your forks. One is about 3 liters, the other about 6 liters. They are designed to use either a solid cap or a siphon tube to connect to your vent line. I don't use mine often so I didn't bother with the siphon hose. By the time the original tank is low, I need a rest anyway, so I just take it of the forks and pour into the main tank. Lists for about $100. Usually there are some listed on eBay.

Here is a follow up. I put the bike back together and found that it was running poorly. I realized that the very old air filter was causing an over-rich condition so replaced that as well. Between these 2 changes I needed to correct the jetting by adjusting the clip on the carb needle. The bike now runs better than it has since I bought it several years ago. Smoother running, better torque and great sound. Not louder, just more clean running sound. In my case, I think it was well worth doing.

I checked my center muffler a while ago and it was very badly carboned up to the point wherre the hole in the center pipe were completely clogged. This prevented the gases from expanding as they were intended to. First, I soaked it in diesel fuel overnight to dissolve as much of the gunk as I could. Then I did burn out the rest of the diesel. I got it hot enough to burn out the gunk that had built up over the years. After I burned it out, I could see the perforations in the center tube. I cannot tell if I burned out the packing but I will say the bike runs smoother and sounds better. I do not like a loud bike and I do not think it is any louder than it was before. Before cleaning the muffler and replacing the very old air filter, I kept fouling plugs and had to lean out the bike by moving the clip in the carb needle. After cleaning and replacing the air filter I was able to move the needle clip back to it's original position and the bike runs and sounds great. Definitley worth doing in my case.

I see what you mean - welding is not an option. Funny story. My riding buddy and I were going to an 2 day event just 2 weeks ago. We drove over 200 miles with the bikes on the trailer. We arrived, fired up the bikes and rode a couple hundred feet before he tried to use his rear brake. No pedal present. He thought he was done for the weekend. After calling around and asking other riders if they had a spare, I decided to just ride around the area and sure enough there was the pedal and bolt laying on the ground! He reinstalled it and we had a great weekend. I replaced the nut on mine with a self locking nut. I hope you can find it so you have a spare.

There are seals and o-rings in the clutch master and slave cylinders. Both are relatively easy to rebuild. If the hose is leaking you would see the fluid on the outside because there is quite a bit of pressure when you squeeze the lever and the fluid would be forced out through any hole.

I know the one from my 95 JT25 will interchange, not sure about newer ones. FYI, when I bought my bike, it was obvious that the brake lever had been broken before and was rewelded. Weld was fine and I broke the pedal in a different place so I bought a new one from a local GG dealer for US$50 not long ago. You might find someone who can weld it for you for less than 70 pounds. Since I bought the new one I have tried to avoid moving large rocks with my brake pedal and have not needed another replacement.

Most big stores that sell kitchen supplies have them. Used for injecting flavors into turkeys, etc.

This is definitely NOT normal. Trials bikes are designed to have good torque all the way from low RPM. It sounds to me like a very lean condition. I would start with a good overhaul of the carb, and fuel filters. While you have the carb off, take a look at the reeds to be sure they are not cracked or not closing completely. There also might be a bad crank seal that is letting air in, but that's more work to get to.

On my '94 JT250 (same basic engine as yours) , I had the same problem. I switched to ATF and the problem went away. I do find that it gradually drags more and more - then I drain and refill the ATF and its fixed. Clean fluid is the key. Check the fluid when you drain it. If it is brownish it is just dirty. If it is thick and milky looking, you probably have a bad water pump seal which puts coolant in the oil. That will drag like crazy and also it's not a very good lubricant either.

Here is another idea for you. You know the bike starts cold and not hot. So it is apparantly temperature related. When trying to diagnose an ignition problem on a car a while ago, I used a heat gun (or hair dryer). Because I knew the vehicle would start cold, I heated one thing at a time and then tried to start it. You could begin with the coil. With the bike cold, heat the coil and see if it starts. If it does, the coil is not the problem. Then do with the stator, then the carburetor, voltage regulator, CDI, etc. Just be careful if you use a heat gun to not cook things too hot. Don't use a flame torch to do this - remember you are around gasoline / petrol and other things that can catch fire. In the case of the car, it turned out to be the sensor in the distributor that signaled to spark. Good luck.

It sounds to me like a mechanical issue of the slide not able to return to the idle screw position correctly. I suggest remove the cable, the throttle housing from the bars and give them a thorough cleaning and lubrication. If the cable does not move freely after lube, replace it. Also check the spring and needle inside the top of the carb for any roughness or bending. When I got my bike, it had a problme with pulling the throttle on a little when I turned far right. I had to reroute the cable to eliminate this. Just shows how sensitive the carb can be to a little cable binding. Fro your descrition, the plug sounds like it has some "MMT" fouling beginning. MMT is a fuel additive and as that brownish ceramic looking material builds up on the plug it will eventually cause a misfire or even no spark. It acts like an oil fouled plug but when you check the plug looks clean, not oily. Change your plug once a year and you should never have a problem with it. Good plugs are a cheap investment that can help you avoid a DNF. I carry a spare plug stuffed into a piece of rubber hose zip tied to my frame just in case!

I have only had my bike rev to the moon once and it was when I had the tank off and it was running out of gas and got very lean. Kill switch didn't kill it so I just pulled the plug wire off (ouch) which was easy with the tank off. Tip, don't safety wire the rubber tube onto your throttle housing at the bar end. It is designed so that if your throttle gets jammed (by unplanned contact with the dirt) you can simply pull the cable free from the housing and wheel. If it is safety wired you cannot do that.

My bike is an older ('94) TXT so not a Pro but there may be enough similarity that this may help. Under the clutch is the shifting mechanism. There is the shifting pawl with a spring and there are 2 more springs that push some rollers onto the shifting drum. If theyt get weak, it can cause the bike to not shift completely and then it can jump out of gear or into a different gear. I replaced all 3 springs (I think that were aout US$20 total) and now the shifting is much more positive. The new springs have thicker material and definelty apply a lot more force to the rollers. This is a good thing. You also might want to find the you tube video by Jim Snell that shows how to adjust the shifting pawl. It can cause a similar issue with gears not being fully engaged and then shifting by themselves sometimes. Other recommendations: Keep the rubber side down and the feet up!