matt_urban Posted September 2, 2010 Report Share Posted September 2, 2010 hello all hope you are all well my txt 2000 249cc bike has run fine up till last few times ive been out. It hunts and is jerky at slow speeds and top end knock when flicking the throttle quick but not all the time current setup is 3.5 turns out on fuel a 36 needle on 3rd notch down and 30 or .30 pilot / normal plug gapped to .60 / fuel mix is 70-1 and fresh fuel trials syn oil ive cleaned the carb out fitted a new plug and tryed 60-1 and 70-1 fuel mix and its still no better any ideas? i have noticed a bit of pitting on the carbs slider is this normal ? Quote Link to comment Share on other sites More sharing options...
jse Posted September 2, 2010 Report Share Posted September 2, 2010 hello all hope you are all well my txt 2000 249cc bike has run fine up till last few times ive been out. It hunts and is jerky at slow speeds and top end knock when flicking the throttle quick but not all the time current setup is 3.5 turns out on fuel a 36 needle on 3rd notch down and 30 or .30 pilot / normal plug gapped to .60 / fuel mix is 70-1 and fresh fuel trials syn oil ive cleaned the carb out fitted a new plug and tryed 60-1 and 70-1 fuel mix and its still no better any ideas? i have noticed a bit of pitting on the carbs slider is this normal ? 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 Quote Link to comment Share on other sites More sharing options...
matt_urban Posted September 2, 2010 Author Report Share Posted September 2, 2010 ok thanks jon I did not realise you used this forum I will try raising needle up from 2nd down to 4th down it was set to 3rd down and ive tryed 2nd down if it feels better i will try a 35 jet and 2nd/3rd down does that sound like it would sort my problem ? Quote Link to comment Share on other sites More sharing options...
jse Posted September 2, 2010 Report Share Posted September 2, 2010 ok thanks jon I did not realise you used this forumI will try raising needle up from 2nd down to 4th down it was set to 3rd down and ive tryed 2nd down if it feels better i will try a 35 jet and 2nd/3rd down does that sound like it would sort my problem ? 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 Quote Link to comment Share on other sites More sharing options...
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