I have a 125/ 6B motor with the 27mm Bing.This carb has the spring to hold the needle,What is the recommended needle setting,none of the books I have state this.I know I can move it up and down and experiment for best result but I'd like to know what the original engineers recomended.Are these carbs normally sensitive to type of air cleaner this one seems to be particulary so.I have replaced all internal parts in this carb that are subject to wear and the just off idle is still not sharp.
I think generally second from top on clip position. Make sure your needle jet(the little funnel looking one is new as they ovalize with wear. If it is a 276 try a 273. Also make sure the slide does not have a smiley face worn into it.
Thanks Larry I have replaced the slide and the needle jet/needle with new.273 is the needle jet I have.I am just trying to sort the bike and am currrently running the carb open.Perhaps with the aircleaner assembly and a 40 degree change in temperature all will become right. Frank.
Frank.
go to this page and see if the 4 part article can help. It was done by John Penton and should answer your questions.
http://autos.groups.yahoo.com/group/PentonRestorationandTechGroup/files/Carburetion/
John D.
Great article and a good tip.After having read it my question is who has a good supply of the all new (in 1973) Penton part no.40-404 Atomizers and 40-405 float needles.The atomizer sounds like the real cure all.Larry do you have some of these?