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Should be. I think the 05' 200 uses the 38mm GasGas forks rather than the 40mm Marzocchi's on the larger models, but a 200 owner may correct me hopefully. Cheers Dude. Jon

No problem, I'll help anyway I can. You can contact me through the GasGas USA or GasGas UK websites under "Tech", but you might want to ask your questions on this forum, there are a lot of smart people that participate here and a group focus works really well. I'm always learning new stuff on this site and some of the answers you get may help other riders also. Cheers. Jon

You really need to pull off the cover, remove the flywheel and take a close look. It can be a crank seal and it does not depend on if the crank is lubed by premix or transmission fluid. You will probably easily tell if it's a seal as it will dribble down the case from the seal usually. Then again, it may be something else, like a leaking case gasket, and the oil will migrate to an area where it can be mistaken for a crank seal. You probably want to fix that before riding the bike anymore. Not quite so bad with a Pro as the trans fluid will go down but if it's a non-Pro engine, it will have an adverse effect on your jetting requirements and can lead to engine damage. Jon

Try this site: http://d-mis-web.ana.bris.ac.uk/personal/H...f/media/gasgas/ and download the forks video, it should answer all your questions. Jon

Nick's right, you always want to check the wiper for cracks and also the bushings, but they rarely are worn on a bike as new as an 04'. From the diagram you give, you have the Marzocchi 40mm steel tube forks. The Marzocchis are a little different from the 38mm GasGas forks in that they take about 290cc's of fork oil, 5 weight if you like them "springy" and 7.5 (ATF works well for that weight) for "normal" performance, but the other difference is that the Zoke's cartridges usually do not fully bleed down when the forks are drained, so the best way to set them is by fork oil level, which is 180mm for the steel tubes (springs out, cartridge bled, fork compressed). Jon

Hi! Just tell the welder that the frame is ChroMoly and he/she will know what to do. Cheers. Jon

Kevin, On the front, left side of the cylinder just behind the exhaust area, there usually is a cast circle and it will have "GG25" for a 250 cylinder or "GG28" for a 280. Jon

Thanks, Dan, Sometimes I think I'm more nut case than hard core. Here's a shot from the other side.

I think we need to establish if it's a Pro or not as they are totally different (and only the later Pros have a black sidecase, earlier ones are "silver" also). Looking at the clutch cover, does it look like you can get at just the clutch by taking out some 3mm Allen buttonhead capscrews (4, I think?) and removing a cover (the rest of the sidecase stays on and you don't have to remove the kickstart) or does it look like you have to remove the whole sidecover to get at the clutch (and start by taking off the kickstart)? Jon

The only "sleeve" I can picture inside a final muffler is the perforated core of the pipe that is inside the muffler proper. If that is loose, you'll want to take off the end cap and re-pack the muffler before installing it. If the perforated tube is loose inside, the harmonics inside, when the engine is running, will bounce that steel tube around enough to wear through the aluminum tubes/sleeves it fits in and the tube will not be properly aligned, causing power loss. Jon

Thanks PeterB, I had forgotten about that ball bearing. In just about all "normal" engines (i.e., not Pro), there is a loose ball bearing in the system that goes from the servo cylinder to the clutch pressure plate, usually under the "mushroom" that presses on the clutch plate and it often falls out without notice. Course, the Pro has that little thin thrust washer on the kickstart shaft that sticks to the sidecover when you take it off and then falls off onto the dirt every time! Jon

Matt, The o-rings are necessary to keep vibration from wearing the metal parts, as well as sealing. If you are in a bind and don't have any o-rings that for the inside of the final muffler, wrap multiple layers of plumber's thread sealing tape around the mid-muffler spigot (to get a tight fit) and then smear on a little hi-temp Silicone sealer, install the final muffler and let set overnight. The thread sealing tape is Teflon and will allow a little movement between the mufflers and help seal the joint. "how should the round peice which sleaves over the center section be placed, should it be loose inside the silencer? or protrude out?" not quite sure what you mean by this, but there should usually be a slight gap between the mid and final mufflers and each one fits a little different. Jon

I hate when that happens! It could be a number of things but it's difficult to tell till you start to pull the engine down. I'd start by taking off the clutch cover and look there before pulling the engine out of the frame as it may be something you can repair without a full extraction and breakdown and it might save you a lot of time. Jon

Point well taken. You're right about the carbon reeds making a big difference and they are one of the reasons that allows the V-force to work as well as it does. The Tassanari prototypes were phenolic/fiberglass reed composition as carbon was relatively rare at the time. Like you say, the reed/manifold setup can have a big difference in low-end power delievery, even in older bikes. I don't know if the photo will process, but it's of a one-piece aluminum manifold/reedcage for a TY350 I made years ago using lost wax casting (like jewlery is made) and used 6 dual-stage reeds. It made a significant change in the throttle rsponse. Jon

I just looked up their website: http://www.mototassinari.com/ and didn't see any applications for specific bikes. You may want to contact your Beta dealer, I'm sure they will be able to find out. Jon

My guess is that the V-force you have is designed for the smaller carb on the earlier models. You may want to return it or if you want to use it, you'll need to enlarge the inlet on the block to fit the manifold. I assume that, when the inlets are matched, it should work fine but I'd have to look closely at the block to be sure. Jon

Yep, that's me, but don't tell anyone, my reputation is bad as it is.... I wouldn't worry about lowering the clip (meaning, go ahead and do it). Each engine is a little different and the same jetting you are running might not work as well for another bike. Same for the air/fuel screw adjustment, it's not a static number of turns but really needs to be set for that specific engine running under those specific conditions. I was riding with a friend today, (helping set up next weeks Trial) that also has an 07' (280, not 250) and he had been having some jetting problems and I machined a #120 jet for him last week for him to try (118s were the largest I had). He said the 120 fixed the jetting problem and the bike runs great. This was a little surprizing as a 118 I run in my 280 would be a little rich for some other Pros. I don't know if this is specific to the 07', but some apparently run better with the 120 and maybe yours is one. I'm not aware of any 07' features that would dictate that jet size, which is larger than "normal" for most 280s. Cheers. Jon

You're correct, the Beta is four petals, but still only a two-sided reed block, whereas the V-force is four-sided and often eight petals. I think the V-force block is significantly different and it's function is irrespective of the reed material-carbon fiber-which is common now in reeds used in Trials engines. Even just considering the reed petal itself, the use of carbon fiber is only one of the factors that dictate it's performance and some other considerations are the weave pattern, resin composition, petal width-length-thickness, radius at tip, free length vs. clamping footprint etc. I didn't want to get too complicated in discussing the V-force, but here's another thing to look at: the angle of the block where the reeds sit in relation to the centerline of the block is called the "half angle" in block design. The V-force is not simply two blocks together but the centers are angled inward on purpose, so beside the doubling of effective tip area, the design helps to shape the fuel/air charge and therefore maintain it's velocity Jon.

The 250 is a sweet bike, they are still kinda rare here but once you ride one it's easy to fall in love with the power delievery. 91 Octane is just about tops for pump fuel where I live also. As I remember, the recommendation is for 92 Octane, but I would think that a "good" 91 should work well if the jetting is correct. As pump fuel octane is an average of Motor Octane Number and Research Octane Number (R=M/2) all pump fuels are not created equal and theoretically, pump fuel with a higher MON that results in the stated average would be a better fuel for our use as the MON research is conducted under more "severe" conditions. A 120 main sounds fine, especially during break-in when frictional heat will be a little higher (I run 118/38 jetting in my 280, but that may be a little "rich" for other 280's and each engine is different). You might want to raise the needle a notch or two (lower clip) to try to clear up the ping as I'm assuming that the "higher rpm" is around mid-range, where the needle setting would have an affect. The base gasket will look thin and I wouldn't worry about it. Gaskets of differing thickness will be used at assembly to set the squish clearance. I don't see any problem with sticking with the 50:1 during break-in (as for premix ratio, you can always change later, within reason, to what suits you) and not make any decisions about gaskets or spacers until you get some solid hours on the bike. It will usually run better (and smoother) as time goes on so your performance baseline will evolve (and any modification decisions during that time will be static) during break-in. Most riders I know are very happy with the 250 without any modifications. This is just "top-of-the-head" stuff and I'm sure that riders that have more experience with the 250 can give you some better advice. Jon

I guess I'll poke my nose in here (I know, as usual).... Some time ago (geez, it's got to be 10 years or so) , one of my Pro riders came back from Belgium with two of the reed cages for us to test. The were made by Moto Tassanari (I understand now V-Force) and had not been released to the public yet. They performed very well and are essentially two reed blocks stacked on top of each other and the idea is that, simply put, with the added surface area (four-sided), you will get essentially double the amount of flow at the same reed opening measurement of a single (two-sided) reed block. There are other details relating to Fluid Dynamics, Harmonics blah, blah, blah, that make them work well, but the main reason, as I understand, is increased flow at low tip openings. Boyesen reeds also work well and to my knowledge, they are the only true "dual-stage" reeds as Eyvind Boyesen still has an active patent on the design. Jon

True. I've also heard a lot of stories that promote either side of the synthetic "controversy". I think that there are so many other variables that contribute to the end result that it's difficult to effectively evaluate causal factors. I've run my bikes exclusively on full-synthetic and my air-cooled TY has over 23 years of use on the lower end with no signs of a problem and less than normal top-end wear. I would guess that if a rider takes reasonable care of their engine and uses a ratio appropriate to the type of oil and riding conditions encountered, it shouldn't matter much what they use. Jon

There are a couple of things I've done to my 280 and other than the special long headpipe I made, should be fairly easy for you and all mods are reversible if you don't like them. The stator plate is fixed on the Pro and although you can slot the Hall Effect sensor (magnetic trigger) mounting bracket, you may want to try that as a last resort. The black tube Domino helps a lot. It has a lower ramp that pulls less cable per degree of turn of the throttle tube. Boyesen dual-stage reeds smooth out the low RPM delivery. Lowering the gearing often helps. I tried the 10-T countershaft sprocket, which helped but now run the stock 11-T countershaft and a 44-T rear sprocket, used for the 125/200 models. Helps me to not get where I'm going before I'm ready. The Montesa 4RT guys love the 44 and have scooped up much of the GasGas dealer stock around here. I think the 07' comes with a 43-T rear (my 02' came with a 42-T) and you can get the GG sprockets in 41-T, 42-T, 43-T, 44-T, 46-T and 48-T, so you might want to try a 44 or maybe even a 46. I like to use the 11-T front as I think the 10-T coils the chain a little too much for the 520 chain. Straight race fuel will soften the low RPM response by lowering the IMEP (Indicated Mean Effective Pressure). Jon

As far as I know, there are no rules requiring them in the U.S. I never liked them as I found the edge of my palm scraping against the throttle side (fixed) bar end and I had to take them off often to clean the gunge out of the throttle tube. When the sealed ball bearing throttle tube bar ends came out I bought a set and really like them and have them on both bikes. The throttle end is sealed against dirt and the bearing makes the throttle extremely smooth and consistant and the heafty bar end takes a big hit (often with me...) and does not deform. Up to then it was guaranteed that a newly installed set of grips would have cut ends within 5 minutes of the next ride. Jon

That's for the key lock to secure the forks at full lock, supposedly to prevent theft or, at least, to keep our criminals in better shape by having to carry off the whole bike. Jon

Probably the best way to determine year and model is to use the VIN number : http://www.trialspartsusa.com/diagrams/GAS...IS%20NUMBER.doc Trialspartsusa also has the GasGas Museum website, very helpful people. Jon