jse

80:1 seems to work fine for me also. I've run that approximate ratio for the last 13 years in my watercooled bikes and the results in performance and reduced engine wear have been satisfactory. I do, however, only mix in a one gallon U.S. container and use only fresh fuel and a gallon usually lasts the whole day. My race fuel that I use is stored in a well-sealed steel container and as soon as I get it filled I add a fuel stabilizer and so far I've never had a problem with stale fuel, which will cause hard starting and poor performance. Jon

I'm trying to remember the capscrew size of the Jt head, but I think they go to about 12 ft lbs (16 Nm) and the cylinder base nuts to about 18 (25 Nm) ft lbs. I'm pretty sure the head capscrews use an o-ring under the washer, if so, be sure to grease them so they don't bind and tear during installation. After running for a time and cooling off, it's a good idea to re-torque them to prevent future loosening. Jon

And don't forget those two small capscrews on the back of the engine case that clamps on the pivot. Jon

"That brings back some memories. Sean Carlin is an old friend and we where away on holiday with a group over at Port Lincoln when Sean was talked into entering the Tuna Tossing. Sean is a big bloke around 6'6" to 6'8". Used to drive a Subaru and looked out the rear side window when he wanted to change lanes." Sean looks like he knows what he's doing! I had a friend who didn't like using the rear-view mirror and when he turned around to look to change lanes, he's would always steer into that lane (we automatically tend to turn in the direction we look, which is why you don't want to look at a rider coming towards you on a single-track trail, you always look off to the other side) and it was great fun to ride with him.... Copey, the Octobertest is the 18th and 19th of this month. I think Pat and possibly Phil will be there, haven't heard personally from the other Pros but I think Louise Forsley might make it. I'll be out there this weekend setting up and will be there when I get back on the 15th. Come'on up and see us, you know how much we love to hassle Texans! Jon

Then, not to worry, but you may want to put a hose on that to direct it away from the electrics. Jon

First guess is that the waterpump seal and shaft will need to be replaced. In rare circumstances, if the overflow hose on the radiator cap is crimped, pressure can force coolant past the seal into the bearbox. The fan should be working as soon as the engine starts to overheat and you may want to use a 12V battery to check it's operation. If the fan works when hooked up to the 12V source, the fan module is probably the 2nd thing to check and 3rd is the output from the stator system. Always check the simple (and cheapest) things first, such as a bad ground or malfunctioning connection. Sometimes wires will get pulled out of the connectors and corrosion will form at the ground point. Jon

"wheelies" are very important in Trials, not necessarily the long, flashy, around the corners ones, but just a few inches to a foot to start with. You'll need them to go up steps and probably starting uphill on a small slope is easier to begin with. Also try small steps by giving the bike a little throttle to extend the forks out to be able to "absorb" the step and then unweight the rear to glide up the step. Timing is very important so don't get discouraged at first, it will get easier as time goes on. Jon

They won't let me enter the cow chip tossing contests here, as it's very well known in the Trials community that I'd rather shovel it....... Jon

You probably have the diamond shaped factory muffler on your JT and short of cutting a patch out of the back and re-packing it, I'm not aware of any other way to quiet it down. I think you could also get the JT with the larger muffler that was re-packable but I'm not aware of a bolt on aftermarket one available. Jon

Welcome! The Oset is a neat little bike. I had a lot of fun watching the World riders do tricks on them at the Duluth World Round in 05' Jon

Found this on a blog I subscribe to: Oddee.com that chronicles the oddities of the world. Those Aussies know how to party and I'm checking my calendar for January! Course, here in Oklahoma, WE got the cow chip toss......one of our towns has a festival built around the "Great Toss". Jon Tunarama: the Tuna Tossing Festival (Australia) The Tunarama festival is held in Port Lincoln, on the tip of Eyre Peninsula, over the Australia Day (26 January) long weekend. When the festival began in 1962, it was intended to promote the emerging tuna fishing industry in Port Lincoln. Tuna fishing is now one of the town's biggest industries and Australia's largest tuna cannery is located there. The highlight of the festival is the tuna tossing competition. Ex-Olympic hammer thrower, Sean Carlin, holds the record for the longest toss at 37.23 metres set in 1998.

I think so too. The VIN research would be the best way to tell, but these photos indicate an 98', first year of the aluminum tank and last year of the three-piece lower fork leg. Jon

That's my guess also. We did a lot of testing over here and found the Ford Type-F ATF seemed to work a little better under severe circumstances with the newer clutches that have the lighter Belville springs, rather than the Dexron ATF, which seemed to provide a little less "bite" when hot. Jon

The 09' 250 Raga I rode this weekend had a 10T countershaft sprocket and for some reason, it did seem still a little high to me also (I thought it was my old, feeble brain). On my 280 Pro I run a 44T 125/200 rear sprocket as the 9T C/S reduction method seems to generate a lot of internal chain friction heat and the tooth engagement/disengagement process is a little too severe which also exacerbates the pressure/heat. Jon

Hi Peter! The locking washer is important. Also, sometimes, after lapping, the tip of the tapered crank will stick out a little too far from the hub surface due to the fact that it is now imbedded further into the hub and the fastener (nut/bolt) will bottom out against the step at the bottom of the threads of the crank tip without exerting enough "pulling pressure" and the flywheel will come loose quickly. You could use a washer with a center hole larger than the hub hole that will, in effect, extend the outer surface of the hub and the pressure will be transfered to the taper rather than the step where the threads meet the taper of the crank. The thin metal sheet/foil trick (brass will even work better) will "restore" the thickness of the taper so the tip will not be extending out too far and it will also make the surface contact area better as often the hub and crank surfaces will be really chewed up with a lot of pits and gouges, which greatly reduce the contact area. The thin sheet metal sleeve is an old trick from the 1950's as we often used 30's and 40's Ford "banjo housing" differentials in our race cars and they had axles with tapers on the end that fit into the rear hubs with shear keys and were noted to often spin the tapers in the hubs under high-horsepower applications. Jon

A couple of suggestions: go to a hardware store and buy some surveyor's tape (same color as the tape used in your local club Trial) to make up a practice section, you'll find that riding a taped section, psychologically and visually, is far different from the flags. It's kinda like having two sections that are completely and exactly identical, one of dirt and the other of rock, yet the rock section is a lot more intimidating, even thorgh they are exactly the same. Tighter and tighter figure 8's on the side of a small hill will teach you a bunch as you will learn about moving weight all around the bike, peg weighting and smooth transition from throttle to brakes. It's probably the best single practice exercise you can do. Trials helmets are different from MX, for instance, the "cut out" at the back of the neck is higher so when you lift your head up while standing, the brow of the front will not drop down and push the helmet/visor down into your field of vision. The MX boots are usually heavier, have less flexibility at the ankle and have soles designed to slide, rather than grip. As a step forward (no pun intended) you might have the MX boots you have re-soled at the local cobbler with a Vibram lug pattern for grip. You'll be much happier the first time you have to dab in a muddy, mossy slick rock section. You can keep them as a spare after you get new Trials boots. Jon

Ooooooooooooooooooo, I'm in love. Just rode the 09' 250 Raga today while we were setting up the club Trial for tomorrow. That is one sweet bike and I like that engine better than the 280/300, plenty of smooth power, like my modified 280, and it starts first kick, every time-no choke. It's got the Sachs shock and Zoke aluminum forks and they work really well together. The frame may look spindly in photos but is quite stout in person and the fork stops are a thick pad that can be replaced in a second, nice touch. The muffler mounts are now beefy and the carbon fiber final muffler looks heavy duty too. I'm on the list for the 4T when it comes over here, but the engine mounts look the same, maybe I could just get a Raga engine and switch engines now and then, the best of both worlds.... Jon

The key does not hold the flywheel to the tapered shaft. It is only used to align the flywheel when installed. What keeps the flywheel from slipping is the special machining of the tapered shaft and flywheel hub. The flywheel hub is bored with a slightly (.001") different taper so that the hub is what's called an "interference fit" with the taper on the crank, which is why you need a puller to get it off (you wouldn't need a puller if just the key held it on). Sometimes, when the hub spins on the shaft it will ruin the surfaces of the tapers, and my guess is that if you look closely you will see the machined surfaces now rough rather than smooth, which means that, besides the loss of the inteference fit, there is less contact area. Short of replacing the flywheel and crank, you could try this: take some fine grinding compound and put it on the taper and install the flywheel and turn it to smooth out the surfaces until the contact areas are relatively uniform (bed the hub and shaft together). Then some very thin copper sheet (almost like foil) can be cut to put on the taper (this will fill in the irregular contact areas), use some red Loctite and torque the flywheel to about 40 ft lbs and let the Loctate cure. I'm sure others have some good ideas as to how to repair the situation also. Jon

Neat! I know S3 makes a lot of aftermarket parts, but I understand they are the company, under contract, that makes all the stock GasGas cylinders for all the Trials bikes. Jon

I would think the next step is to get a syringe and force some brake fluid into the bleed screw up to the M/C. Once the line is filled, it's a lot easier to bleed the system. If that does not work, I'd go back (reverse engineer the processes) and carefully inspect each change you've done, starting from the most recent back to the first and don't assume that any were done correctly (the part you overlook will most likely be the cause of the problem and over confidence has blown up many a race engine). Take that particular piece apart (and keep track of how the parts were assembled by laying them out in order of disassembly), inspect each one carefully for improper installation/damage, make sure the re-assembly order is correct (use a diagram if at all possible) and carefully re-assemble them. Jon

Peter, From what I remember, the coating is made up of a series of vaporized wires, I think it was 8-10 each of the Moly and steel (not sure, however) and the cylinder was thermo-normalized and then rigid diamond honed. I worked on a lot of bore plating types, such as the early Yamaha chrome, Suzuki Boron-Composite, Kawasaki Electrofusion and the Honda Nikasil. The Electrofusion plating was a lot thicker than the Nikasil and therefore easier to work with when it came to modifying ports, but it does look like someone acid-etched the bore when you first see it. Jon

Peter, That sounds like Kawasaki's electrofusion process they used during those years. It's a process that leaves a porous, hard coating of molybdenum and steel permanently secured to an aluminum bore by using high voltage during manufacture. As I understand, the process involved thin Moly and steel wires located inside the bore lengthwise and then vaporized with high voltage. Sounds kinda Dr. Frankenstein-like in it's process, but the coating was quite durable when properly cared for. Jon

Spencer, is that the S-3 kit http://www.trialspartsusa.com/racing-parts.html ? That sounds like my kind of hybrid. Jon

Try http://www.gasgasmuseum.com/ for a start. The German site at http://www.gasgas.de/ may have a parts manual under "Esatzteile" but some are difficult to read. Jon