jse

The best I can do is off a German GasGas website: http://www.gasgas.de/data/etk/200508051525...l%20JT%2025.pdf but it's kinda hard to read well, so I don't know if it will help. Jon.

I agree. The fine particles are a normal wear indicator (mostly from trans and primary gear teeth). I would, however, be a little suspect of the silver color in the trans oil (depending on how much aluminum is in the oil) as that would possibly be something wearing off the particles from the cases or clutch, which is not usually normal. You might want to look underneath the clutch, idler gear etc. just to be sure. Jon

My son has a JTX320 (the JTX is the 1997 model) and we found that 650cc's of Dexron III ATF works well. Change it often and you won't have any oil related trans problems. Jon

The mid-90's engines were designed to run on a minimum of 95 octane fuel, which, if you live in the U.S., is not available at the pump anymore. In order to rule out fuel as a cause, try mixing at least a 50/50 mix of high-octane pump fuel and 110 race fuel to see if this aleviates the condition at all. Jon

It's a 280 and NOT a Pro, but a TXT "Edition" type model. The plug for a Pro should fit the TXT as I remember. Jon

Your plastics are telling the truth.... Jon

Me too. If I'm messing with ignition setttings (or cam settings), I use the "positive stop" method to find TDC for that specific engine to give me an absolute starting point. As I remember, it was developed many years ago by a guy named Ed Iskenderian, who was a master cam grinder for the flathead Ford V8 engines we were running in our race cars at the time. We needed to find TDC accurately to be able to degree in the cam during installation. How it's done is to attach a degree wheel to the engine (I use a small wheel with several strong magnets attached so it easily attaches to the flywheel and mine is old enough to have "AJS" inscribed on it.... and make a pointer. Use a piston stop tool (looks a little like a sparkplug with a long, large projected tip, the one I made has a tip adjustable for depth) that contacts the piston crown a few degrees before TDC. Rotate the crank carefully until it stops when the piston touches the stop, mark the wheel, rotate the wheel back the other way till it stops, mark the wheel. Absolute TDC will be exactly in the middle of those marks. Say the distance is 41 degrees between the two marks, TDC will be 20.5 degrees from either one. Jon

Yep, same stuff ("Teflon" is a DuPont TM), have used it for years and it's saved a lot of levers the way I ride. Jon

I set my levers so I can reach them while back on the bike as much as possible so I can reach them when I REALLY need them, like on a steep, loose downhill. A tip on the loose lever perches, if you wrap a few layers of "plumber's tape", which is a Teflon tape used by plumbers to seal pipe threads and easily obtained in hardware stores, around the bar under the perch, you can snug them down quite well and they will still be able to rotate in a "mishap". Jon

650-700cc's of Dexron III ATF seems to work well in the 01' engine. Change it about every 10-15 hours of use (ATF is cheap) to keep it fresh (Trials bikes are kinda hard on tranny oil). Jon

Stork, You know what? I think you're correct about the reluctors. My MSEE buddies insist they are Hall Effect Sensors, but as I remember, the magnetic pickups in use now have two wires coming out of it, which would mean that they are reluctors, not HES's, which would require three wires as HES's need a current source to operate and reluctors do not. Cool, I get to tell my MSEE buddies they are full of poop and they owe me a beer.... Thanks for the info, seriously, I love learning new stuff. Jon

Copey, Dual pickups, interesting. Most CDI multiple stage systems use a pre-programmed set of "maps" (distinct bell shaped curves of ignition points/RPM in relation to TDC) and they often are essentially the same curve up to a point, say 2000/2500 RPM, where one has a different rate of advance/retard. The CDI uses the same Hall Effect Sensor (the magnetic pickup) to trigger the CDI using either map. In this case, the rider would toggle between the two CDI programs. Dual pickups would seem to indicate a single pre-programmed map (same curve), but one pickup starting the curve 6 degrees (in this case) sooner than the other pickup. Here, the rider would toggle between the two pickups. Jon

"2000 txt 280 (clutch is sticky, isnt disengaging very well when in gear via the clutch lever) (assuming some fresh oil will help alot, as the previous owner hasnt changed in 5 hrs + storage)" Some drag will be normal. Be sure the adjustment screw on the clutch lever is backed out enough to have a little clearance where it meets the plunger at the master cylinder. "From what ive read (please correct if wrong) 750ml of Automotive Transmission fluid, or? (everything i see is Dexron-III, good enough?)" Dexron III works well in this trans and 650cc's, rather than 750cc's, seems to make the clutch a little smoother. "drain from bolt under skid plate (do i remove the skid plate or what?) Fill 750 mls on the brake lever side, allen bolt thing." No need to remove the skidplate. Use a new Allen wrench (or cut about 5-8mm off the end of an old one) so the aluminum plug ("allen bolt thing") is not stripped out. Can someone suggest a fluid that is known to work well with the 2000 txt 280? or just use some canadian tire ATF or similar. Not sure what "canadian tire ATF " is, but Dexron III ATF is what most riders use. Jon

Greg, I understand the MiniMissle is in it's third incarnation and will be up to Booneville Salt Flats-level speed for the launch..... You might want to explain what were talking about to those who are reading this and wondering what exactly the bike launch is. Jon

First, I personally would replace the triple tree. It's a REALLY critical part and you can get REALLY hurt if it breaks. It's probably the lower one as owner's often do not use anti-seize and a torque wrench and don't alternate between the two capscrews when tightening so they end up over tightening, and the capscrews are uneven on torque, which creates stress. The lower tree has the steering axle pressed into it and I think you may have the steel axle. The later ones are aluminum, so the 03' would most likely not fit yours (for instance, the 01' and 03' steering axles are different part numbers- ST950400 for 01' vs. BT280214003 for 03'). Your local dealer can get you one, but you will probably need a press to remove/install properly. As for preload, you might add about 6-8mm to the preload collar to start with, but I'd start with raising the oil level a little (say, add 320cc's of 5 weight fork oil to completely flushed/dry fork leg when servicing them, as opposed to the 300cc's as standard). Jon

Should work fine. Jon

Thanks, Charles. You are one of the enthuiastic core I was speaking of. See you at the Flint Hills 2-Day! If any of you are around Kansas on the 7th and 8th of next month, don't miss the last of the Central Regional Championship Trial events. You'll want to go just for the famous "Bike Toss"......... Cheers. Jon

You might have someone with some carb experience listen to it as it may be something else, not the carb. If the o-ring is gone, you'll need to replace it. Jon

Hi Nigel, I answered your PM before reading this post. Let me know your address at my website e-mail and I'll send you what you need for the 98', no problem. Welcome to the wonderful world of Trials! There are some really good Trials clubs in Arizona. Cheers. Jon

Well, here it is Monday, and the 30th annual Octobertest is now in the history books. The joints and muscles ache, the scrapes and scratches will heal in time. The stress and mental strain of wanting to do a good job and make sure everything is perfect have slowly slipped away. The trailer and 4Runner parked in front of the shop are still jam packed with dirty bikes, muddy riding gear and a ton of Trials equipment that needs to be cleaned, sorted and replenished for the next event. It seems like I've strung several hundred miles of tape up and down ravines and rocks and in the process did more than a couple of "yahoooooooooo!"'s down the side of steep hills. The early morning alarm clock intrusions and the hundreds of miles driven to and from the event venue the last few months setting up the Trial are a blur. I'm pooped. However, those thoughts fade quickly and are replaced with the lifelong ones of the fun of working with an enthuiastic core of clubmembers who gladly volunteer their time off to help achieve a common goal, the joy of finishing off the last of 32 sections and finishing marking a 9 mile loop, of again seeing old friends and making new ones, of seeing whole families having fun together, of seeing new riders starting out on a journey I've loved for 38 years, of seeing young riders with a ton of potential correcting their mistakes each time they rode the obstacles, of seeing a young lady verbally coaching herself through a tough Novice uphill section and finally cleaning it with great style, technique and a whoop of joy, of seeing Pat Smage pick the tough lines just to entertain (and REALLY impress) the spectators, of getting some time to talk with Pat and further reinforce my belief that he is one of the nicest guys in Trials, of again seeing and having time to talk with Tommi Ahvala when he stopped by (another of the nicest guys in Trials), of saying goodby to everybody and knowing I'll see most of them again at the Kansas Central Regional 2-day in a couple of weeks. The happy list goes on and on. Man, I can't wait till next year! Jon

Today I rode the U.S. GG importer's bike, a gold frame 09' Raga 300, which has many of the 2010 regular features on it. The only changes were a 28mm OKO carb and a special V-Rubber rear tire (new, ultra soft type). It was amazingly smooth and easy to control. The suspension (Sach rear and Marzocchi front) worked very well in the wet, rocky uphill creeks I was able to try it out on. I have an 02' 280 Pro that I'm very comfortable on after 7+ years, but I found it very easy to quickly adapt to the new frame geometry. It seems a lot more stable and it sure turns a lot better than my 02' (which handles very well, the 02' frame is a little different than the newer Pros). I think you'll be quite happy with yours. Jon

Here's a few photos of the area for the Octobertest this weekend in the 1700 acre Scipio off-road park in central eastern Oklahoma. We've got some nice waterfalls, creeks, rocks, mud, logs, hills, off-cambers etc....you know, real Trials stuff to play on. The 32 sections are taped and cleaned and the loop is set and the weatherperson says no rain (luckily, we do have a little water in the creeks, but no dust!). Jon

Dan, Obviously, not my personal wording (hence the quotation marks, I try not to be as obtuse) but you know what? I re-read that explanation and I did experience an intense desire to nibble my OWN ear...... Jon

I apologize for the flip comment, it was uncalled for and certainly not indicative of what I intended to express. E-mail is a quite "cold" way to communicate and lacks the tone, volume, cadence and inflection of the human voice, as well as lack of facial expression, and a comment meant to be funny came across as crappy. Copey will vouch that I'm much, much more goofy than I am grouchy. At 140 Nm (about 103+ Ft lbs) and lapped, it should hold well. If it slips again, look at where the crank stub protrudes through the flywheel hub. The end step of the stub is often very close to the washer surface inside the hub and when lapped together, the stub will fit slightly farther down in the hub, sometimes far enough so that the step then contacts the washer. All the torque is then on the washer/stub end area (the stub has bottomed out against the washer) and not on drawing the stub in against the flywheel hub. Jon

O.K., you win. Jon