lpd Posted July 29, 2008 Report Share Posted July 29, 2008 I have a 2000 TXT250. On the gasgas tech page it states 3.5 turns out for fuel screw. I assume this is the first smaller screw? Is this a starting point, I have mine about 3 turns out and it runs good there. Secondly I have a newer rear shock on my bike which looks like an 02 shock. The spring has much larger gaps between the coils than my buddies 2000, both are Sachs, but mine has different colored collar bolts to lock the spring down and a different spring ie: gap between coils. It feels as if though my bike rides raked forward no matter how I adjust the front forks. Rear linkage was cleaned, lubed and is fully serviced no issues. Is the 2002 shock longer than the 2000? Quote Link to comment Share on other sites More sharing options...
peterb Posted July 29, 2008 Report Share Posted July 29, 2008 Hi lpd, 3 turns out is fine for the pilot, 3.5 turns is just a starting point. It is the (smaller) screw closer to the inlet manifold. The 02 PRO model shock is 20mm shorter than the older 95 type models, which may just be the same length for the 2000 model (I am reasonably sure though not 100% sure). By your description, it sort of sounds like you have a shorter shock. A longer shock ie: standard length, fitted to your bike would tend to tuck the front end in from where it is now. From memory, the older shock was 300mm centre to centre, the PRO models are 280mm. Bye, PeterB. Quote Link to comment Share on other sites More sharing options...
jse Posted July 29, 2008 Report Share Posted July 29, 2008 I have a 2000 TXT250. On the gasgas tech page it states 3.5 turns out for fuel screw. I assume this is the first smaller screw? Is this a starting point, I have mine about 3 turns out and it runs good there.Secondly I have a newer rear shock on my bike which looks like an 02 shock. The spring has much larger gaps between the coils than my buddies 2000, both are Sachs, but mine has different colored collar bolts to lock the spring down and a different spring ie: gap between coils. It feels as if though my bike rides raked forward no matter how I adjust the front forks. Rear linkage was cleaned, lubed and is fully serviced no issues. Is the 2002 shock longer than the 2000? The "suggested" setting for the mixture (probably on the left of the screw in the center of the carb body,and a fuel adjustment screw) is only a start and is generally different for all bikes. If there was only one "correct" setting, it would not be adjustable. With the engine warm, quickly "blip" the throttle from idle and adjust the screw in/out until you get the best response. That setting is the "correct" setting for that particular engine, under those specific ambient weather conditions. So, your engine likes 3 turns out on the fuel screw and I wouldn't worry about it. I don't know for sure, but I think the shock centers are the same. You also may have an aftermarket spring, and with the increased "gap" between the coils, I'm assuming it's a "stronger" spring (a higher "rate" spring, in part, is dictated by the number of coils and coil diameter and one of the ways to make a spring "stronger"-higher rate- is to cut coils off it). I'm assuming you have tried backing off the preload collar? If not, try adjusting the collar about 3-5mm's at a time until it works for you. If that does not handle it, you may need a softer spring. Quote Link to comment Share on other sites More sharing options...
lpd Posted July 29, 2008 Author Report Share Posted July 29, 2008 The "suggested" setting for the mixture (probably on the left of the screw in the center of the carb body,and a fuel adjustment screw) is only a start and is generally different for all bikes. If there was only one "correct" setting, it would not be adjustable. With the engine warm, quickly "blip" the throttle from idle and adjust the screw in/out until you get the best response. That setting is the "correct" setting for that particular engine, under those specific ambient weather conditions. So, your engine likes 3 turns out on the fuel screw and I wouldn't worry about it. I don't know for sure, but I think the shock centers are the same. You also may have an aftermarket spring, and with the increased "gap" between the coils, I'm assuming it's a "stronger" spring (a higher "rate" spring, in part, is dictated by the number of coils and coil diameter and one of the ways to make a spring "stronger"-higher rate- is to cut coils off it). I'm assuming you have tried backing off the preload collar? If not, try adjusting the collar about 3-5mm's at a time until it works for you. If that does not handle it, you may need a softer spring. Thanks guys. I noticed that the engine is chunkier at about 2 turns out, but crisper at 3. I'll experiment and see what works for my riding style. I think that the spring may be the difference. Perhaps I should try a lower rated spring. I've tried to back off the preload and the suspension feels dead. If I crank it down it becomes to bouncy. I found a happy medium for the shock, but still feel like I'm leaning forward. Quote Link to comment Share on other sites More sharing options...
lowbrow Posted July 29, 2008 Report Share Posted July 29, 2008 I can tell you about the spring you should have because I tested one from a 2000 TXT280 a few years ago. Its approx 151mm in length and has progressive coils. ID at top is approx 48mm and the bottom end ID is approx 39mm. When tested this spring had an average rate of 68.9N/mm and a range of 68 - 75N/mm. Its sitting on a shelf in my workshop if you want it? Hope this helps. Dave Quote Link to comment Share on other sites More sharing options...
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