wild foamy Posted July 2, 2009 Share Posted July 2, 2009 okay peeps, another question for ya... my DT is now running great, albeit a little rich in the mid-rev range but that doesnt bother me much. anyhoo, if you let go of the throttle and then pull it open again, the engine will respond for a split second, then die for a second and then fire as usual, and it also tends to bog down off the line (often requiring a slip of the clutch to allow it to clear before departing) it also dies if i take a speed bump with too much speed or going up a steep hill and when your riding out with your mates, its kinda a pain in the ass is this related to the mid-range rich running or a completely different problem?, maybe floats too high? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted July 5, 2009 Moderator Share Posted July 5, 2009 okay peeps, another question for ya... my DT is now running great, albeit a little rich in the mid-rev range but that doesnt bother me much. anyhoo, if you let go of the throttle and then pull it open again, the engine will respond for a split second, then die for a second and then fire as usual, and it also tends to bog down off the line (often requiring a slip of the clutch to allow it to clear before departing) it also dies if i take a speed bump with too much speed or going up a steep hill and when your riding out with your mates, its kinda a pain in the ass is this related to the mid-range rich running or a completely different problem?, maybe floats too high? I got that when I put my floats too low. Had to rev and slip the clutch to get going. this is a weak fuel symtom ( for 4 strokes anyhoo!) Link to comment Share on other sites More sharing options...
wild foamy Posted July 5, 2009 Author Share Posted July 5, 2009 hmm, this is a two smoke bike and it sounds more like its bogging down like if i pull away with the choke on, not like if i leave the fuel tap off and go off chasing my mates aprillia down the road only to have it rev up at the traffic lights and cut Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 6, 2009 Moderator Share Posted July 6, 2009 okay peeps, another question for ya... my DT is now running great, albeit a little rich in the mid-rev range but that doesnt bother me much. anyhoo, if you let go of the throttle and then pull it open again, the engine will respond for a split second, then die for a second and then fire as usual, and it also tends to bog down off the line (often requiring a slip of the clutch to allow it to clear before departing) it also dies if i take a speed bump with too much speed or going up a steep hill and when your riding out with your mates, its kinda a pain in the ass is this related to the mid-range rich running or a completely different problem?, maybe floats too high? It is probably the opposite of what you think (rich running) When you snap open the throttle you will lose air speed through the carb venturi, this in turn will cause a pressure increase, this pressure increase means there is not enough suction to draw fuel through the needle jet momentarily and engine revs will increase only slowly. Same thing goes for speed bumps, in the eyes of a little DT a speed bump is a big hill and the corresponding action of opening the throttle to scale such hill also causes the same problem...try changing down a gear for large speed bumps... Link to comment Share on other sites More sharing options...
wild foamy Posted July 7, 2009 Author Share Posted July 7, 2009 even if i change down a gear it bogs and slows me down before recovering , it sounds asif its flooding as it starts to fourstroke. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted July 7, 2009 Moderator Share Posted July 7, 2009 even if i change down a gear it bogs and slows me down before recovering , it sounds asif its flooding as it starts to fourstroke. So why not drop the needle a notch and see what happens. Link to comment Share on other sites More sharing options...
wild foamy Posted July 7, 2009 Author Share Posted July 7, 2009 needle is in its lowest position already Link to comment Share on other sites More sharing options...
barkwindjammer Posted July 7, 2009 Share Posted July 7, 2009 needle is in its lowest position already maybe try setting needle up a notch and then 'lean' the mix? anyhoo hows the moustache coming on ? Link to comment Share on other sites More sharing options...
wild foamy Posted July 7, 2009 Author Share Posted July 7, 2009 maybe try setting needle up a notch and then 'lean' the mix? anyhoo hows the moustache coming on ? Moustache?... O.o only mixture screw i can see is the idle mixture screw, and its running fine at high-RPM/full throttle so theres nothing wrong with the size of the jet Link to comment Share on other sites More sharing options...
JUST ME! Posted July 8, 2009 Share Posted July 8, 2009 needle is in its lowest position already Buy the next length needle from Yamaha! Link to comment Share on other sites More sharing options...
Moderator Cynic Posted July 8, 2009 Moderator Share Posted July 8, 2009 Moustache?... O.o only mixture screw i can see is the idle mixture screw, and its running fine at high-RPM/full throttle so theres nothing wrong with the size of the jet If you are running the needle in its lowest setting and it still seems rich then much as you may protest its the wrong jet. At the moment you have a main jet that is restricted by the needle, reduce the size of the main jet and lift the needle and you will have the same amount of fuel at full throttle and less in the midrange. Link to comment Share on other sites More sharing options...
JUST ME! Posted July 8, 2009 Share Posted July 8, 2009 If you are running the needle in its lowest setting and it still seems rich then much as you may protest its the wrong jet. At the moment you have a main jet that is restricted by the needle, reduce the size of the main jet and lift the needle and you will have the same amount of fuel at full throttle and less in the midrange. Without actually seeing first hand where he is up to it is difficult to advise. What is four stroking and is the mixture actually rich on acceleration? Remove the main jet Foamy and work out whether the needle is clearing the jet at full throttle. Be very careful Foamy if you decide to reduce the main jet size or another big bore may be no more! Link to comment Share on other sites More sharing options...
JUST ME! Posted July 8, 2009 Share Posted July 8, 2009 If you are running the needle in its lowest setting and it still seems rich then much as you may protest its the wrong jet. At the moment you have a main jet that is restricted by the needle, reduce the size of the main jet and lift the needle and you will have the same amount of fuel at full throttle and less in the midrange. Without actually seeing first hand where he is up to it is difficult to advise. What is four stroking and is the mixture actually rich on acceleration? Remove the main jet Foamy and work out whether the needle is clearing the jet at full throttle. Be very careful Foamy if you decide to reduce the main jet size or another big bore may be no more! Link to comment Share on other sites More sharing options...
JUST ME! Posted July 8, 2009 Share Posted July 8, 2009 If you are running the needle in its lowest setting and it still seems rich then much as you may protest its the wrong jet. At the moment you have a main jet that is restricted by the needle, reduce the size of the main jet and lift the needle and you will have the same amount of fuel at full throttle and less in the midrange. Without actually seeing first hand where he is up to it is difficult to advise. What is four stroking and is the mixture actually rich on acceleration? Remove the main jet Foamy and work out whether the needle is clearing the jet at full throttle. Be very careful Foamy if you decide to reduce the main jet size or another big bore may be no more! Link to comment Share on other sites More sharing options...
JUST ME! Posted July 8, 2009 Share Posted July 8, 2009 If you are running the needle in its lowest setting and it still seems rich then much as you may protest its the wrong jet. At the moment you have a main jet that is restricted by the needle, reduce the size of the main jet and lift the needle and you will have the same amount of fuel at full throttle and less in the midrange. Without actually seeing first hand where he is up to it is difficult to advise. What is four stroking and is the mixture actually rich on acceleration? Remove the main jet Foamy and work out whether the needle is clearing the jet at full throttle. Be very careful Foamy if you decide to reduce the main jet size or another big bore may be no more! Link to comment Share on other sites More sharing options...
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