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For all things GasGas (and your manual): http://www.trialspartsusa.com/tech.html . Great site for GasGas owner's and Jim Snell does a lot of "how to" videos on YouTube. Jon

You have the "large body" Dellorto on the 370, the only year and model it was on (they are common on Fantics). I doubt that an air leak or jetting is the problem as the symptoms are not consistant (air leaks and jetting usually have constant, not intermitant symptoms). I'd look for a problem with the cable such as frayed at the throttle housing or kinked by the fork clamp somewhere. You should also check the carb very carefully and look for a problem with the slide hanging up in the bore, sometimes caused by grit getting past the air filter element. Jon

It could be that fan module, but you need to check, with the bike running, for 12V getting to the fan. The bike can still run with no power put out to the fan/lights as your bike has two distinct generating systems (two sets of coils on the stator), one for fan/lights and another one for the CDI ignition. Jon

Telecat, The U.S. standard for pump fuel octane is a combination of MON and RON divided by 2, so it is an average. For motorsports use the MON number is more significant as it is derived by more severe testing standards. Jon

We've found that 650-700cc's of Dexron ATF works well in that engine. Jon

Got one out of parts and measured it: 3mm wide 15.3mm long 5.9mm tall Jon

The TrialsPartsUSA site has the 2001 TXT parts manual, which is essentially your engine. Do you have the 96' JTR 370 (blue plastic) or the 97' JTX320 (silver plastic). The JT model was earlier than 1996. Send me a PM, I might be able to help you out with some other things. Jon

Questions: 1. What temp SHOULD the thermo trigger at / fan come on at? A: I'm guessing around 180/190 F. (about 82 to 88 C.) 2. Is there a "range"? A: See above, but still a guess as that seems to be a good operating temp for most engines. 3. What temp should the engine operate at, ie, once I do get the fan/cooling fixed, how will I know if the engine is being cooled properly? A: Actually I never checked the temp range in an operating Trials bike. With proper jetting, there will be a lack of pinking and good throttle response and power output will be consistant. 4. I did not "flush" the contaminated coolant, but it drained for some time, on the kick stand. Will check that first. If the head's O-ring is bad, will that quickly wear out the seal in ~5mins? A: A leaking head o-ring will not wear out a W/P seal. The only related problem would be when the radiator overflow tube is crimped and the pressure from a leaking inner head o-ring will force coolant past the seal lip into the transmission case, but that still will not cause wear to the seal, only malfunction. 5. I am 99% certain that I did not damage the wp seal upon installation, (I use very $$$ ****zu seal grease on all seal installations, care, etc), so is the "OEM hard brown seal" the best one, or is there a modern Viton rubber seal that is a better replacement? A: Not that I know of. 6. I have never been a proponent of running 100% antifreeze, esp in an engine so needful of colling ability, but since it "does" lube better than a af/water mix, is this what I should do in order to extend wp seal life? (In other words, aspartame and distilled water would be my preference to help cool this hot-running situation/engine, but I am scared to do that, with its apparant wp seal friction-problem---correct?) A: A 50/50 mix of auto anti-freeze and distilled water should work fine. My experience is that there is not a seal lip friction-problem in these engines under normal conditions. You do not have a problem with an engine that, as a rule of design, runs hot-you have a problem with one or more failed components that do not allow the engine to normally cool itself. You need to fix the cause, not the symptom. 7. Did not see "bubbles" when I started the engine up, but did notice that the coolant "spurted" out in a consistent little spurt, as if the waterpump had a lot of "drive"---will test that second. A; With the cap off, under idle conditions, the coolant usually does not spurt out the radiator neck from my experience. So sorry sir for all the Q's, but there is SO little info on these engines/bikes, and I cannot afford trial [no pun intended] & error! No problem, let us know how it goes. Trials bikes are a little different to work on than most bike engines. Cheers. Jon

(1) Did you flush out all the old trans oil with the water in it? It does not take much water to color the fluid and you may need to run the engine and change the oil again, the seal may be fine but you still have residual water. (2) Coolant in the trans oil will generally not be the primary cause of over-heating and steam out the overflow. In fact, rarely does overheating occur before the rider notices the color of the trans oil is not right. I'm assuming you rode the bike for a time before buying it and if it did not overheat then, there is a better chance that something you did or not do caused the new problem. In that case, you will want to reverse your last proceedure and check each step in the process. (3) The cause seems to be lack of coolant circulation due to the rapid onset of overheating, see answer #2. It may also be a leaking head inner o-ring that will need to be replaced. Fill the radiator with coolant and with the cap off, start the bike up. If you see bubbles coming up, they are most likely exhaust gas passing past the inner o-ring into the cooling system. (4) A pan of water warming on the stove, a thermometer and a meter hooked up to the thermoswitch leads will tell you the temperature at which the switch works (or does not). Jon

That's really unusual, but I'd first look for a sheared Woodruff key in the flywheel hub allowing the timing to change radically. Jon

Ah Copey, my Texan Luddite friend. Just trying to add some "why" to the "how" of engine tuning and maybe clear up some possible misinformation in the process. No new bikes, but I think I need some more coffee...... See you at the Octobertest? Jon

Each engine is a little different and it will be time well spent to fine tune your bike to the conditions you run it under. The milk-chocolate color plug is not an absolute and Trials engines are somewhat different when it comes to plug readings. You will probably find your plug will end up having a slightly darker color in most cases when it is running fine. In Trials engines, plug color gives a much more general indication of mixture condition due to the lower RPM range using several overlapping carb "circuits" and the on/off throttle settings, rather than just the needle/main settings under relatively constant load that most other competition engines run under. The plug color will be a good "gross" indicator of carb tuning but the engines behavior is what you will use to tune it. Trials engines will cough, bog, rattle, stall, sputter, hiccup etc. when they need attention in the carb department, so keep track of what your engine does and the conditions under which it does it so you can post the results and other riders can help you get it sorted out. Good luck. Jon

Cool. Let us know how it works out. Jon

"Info on all" is like asking for all information on Fords or Chevys, but I understand your concerns. The 02' TXT is pretty bulletproof and like dschigoda mentioned, it was at the summit of it's development. Good solid bike and no unusual problems I'm aware of. Of course, the condition of the specific bike will be important, so if you can, take someone along that is familiar with Trials bikes and will know what observable details reveal possible care/abuse. When you see a bike you're interested in, post it and there are a lot of riders who can give you their opinions and this can help you in your decision. Welcome to the club! Cheers. Jon

Hi Mike. I couldn't quite figure out what was the question in the first post, as to the last post: The answers are no (for most later model "Edition" engines) and yes. Look at the pressure plate and you'll see a cast line as part of one of the spring holes. On one of the spring towers that stick up through the spring holes in the outer pressure plate you'll see a line embossed in the top of the tower. Those "lined" parts need to go together i.e. the tower with the line at the top (across the threaded hole) needs to go through the spring hole with the cast line on it. Let us know if that does not solve the problem. Cheers. Jon

Hi Gordie. Here's a few tips that might help: Before installing the Boyesen reeds, use a little 600 grit wet/dry sandpaper to very, very lightly radius the edges of the reeds (maybe two light passes with the sandpaper at most) to remove the sharp part that is the result of the manufacturing process. This will extend the life of the reeds by removing the "stress riser" where cracks and fraying can develop. Use blue Loctite on the screws and do not over-tighten them when installing. While you have the reeds off the cage, you might take a small file or Dremel tool to match the manifold, if necessary, to the cage to give a little better flow. It usually does not take much to reduce internal turbulence and the price is right-free. The D36 needle usually works well and the middle groove is a good place to start. The #35 can be a little lean for some engines so if you have any off-idle problems, consider a #36 or #38 pilot. Switching to a #80 starter jet really aids cold starts (or use a .031" drill to enlarge the #60 jet). The 120 main can be a little rich so you might end up with a #118 or #116 main jet. There is no standard final setting for the air/fuel and idle speed screws. You'll want to set the idle speed with a warm engine, in gear and the clutch lever pulled in normally (not all the way to the grip). Adjust the fuel screw by quickly blipping the throttle from idle (warm engine) and adjusting the screw in/out for the best response. The fuel screw final setting will vary with temperature, humidity, barometric pressure etc., and is the reason why it is adjustable. Jon

There were two distinct models available in 02'. Are you looking at a TXT "Edition" model with the older type engine or the newer "Pro" model (actually the "TXXI" model)? Jon

Hi Dave! I weigh just a little less than you so my GG forks are set up in your weight range. I run the compression (black knob on left) fully out and the rebound (red knob on right) fully in. I've added 7mm to each preload spacer (I think 1" schedule-40 PVC is the same size as the stock grey one's installed) and use 315cc's of oil (5-weight in my case) in each leg to raise the oil level slightly to avoid bottoming. The adjustments are high-speed, pop-off, fine tuning adjusters so you will not notice any change just pushing on the forks. When you re-install the forks have all the fasteners loose except for the upper tripleclamp (the tripleclamp capscrews go to 18 ft lbs-about 25 Nm). You'll want to push up/down on the forks to center them and then tighten the lower tripleclamp capscrews (with the double set of capscrews tighten them alternately in 5 lb increments up to 18 ft lbs). Center the forks again and tighten the axle. Center again and tighten the axle clamp screws. The fork brace is always installed last. This proceedure will avoid fork binding. Jon

Wow, great photos and great story. Your GasGas looks like a 1988 model, is it? Jon

Lots of Trials guys up where you ride. Let me know if you run into any problems with your 350. Cheers. Jon

Hi Shane. Very informative post in the Monoshock section. As you now know, the 350 piston/rings are hard to get. I'm sure there is a bunch of them stashed away in a dark, forgotten corner of an old Yamaha dealer's parts warehouse somewhere. Where are you located, over on the Fracy side of Canada? Jon

I'd try to keep the bend in the upper part of the lever as close to the frame as possible. With the lever too far forward you run into the possibility of over running the partial gear where it engages on the kickstart idler gear and causing damage. The newer spiral shafts on the kickstart mechanism have a different degree of spiral cut to engage (lock up the kickstart mechanism) the lever sooner in the rotation. Jon

That might do it. The #30 seems a little lean for me. The air/fuel ratio normally goes lean in the transition from the idle circuit to when it starts to draw from the needle jet (which is where you describe the pinking problem to be) so that's why we need a pilot jet to "pilot" the A/F ratio and not have a stumble each time you open the throttle. Jon

Hi again, Matt. I got your e-mail to me and returned a reply and suggested a 35 or 36 pilot but try raising the needle one notch first. The slide pitting is not normal and may mean some grit is passing by the air filter so give that a check. Cheers. Jon

I'm converting all my old VHS Trials tapes to DVD and I remember one of Jordi teaching in Spanish, with voiceover in Italian and Japanese subtitles...... Jon