I need initial screw settings for a YFM80 Moto 4 carburetor. I just rebuilt it but can't find initial screw settings.
By rebuilt, do you mean the carburetor?? ..or the engine??.. if you rebuilt the carb and you did not remove these screws ( and count the revolutions out from lightly seated), then you did not do the rebuild the carb correctly.. sorry.. What, exactly did you do to the carburetor?? Please reply on here to me..with details!!
I cannot understand why someone that claims to have "rebuilt" a carburetor actually missed the BASCIS of carb rebuilding 090.. the air screw (the one on the angle toward the back of the carb has/is connected to the pilot jet system and the idle system, the passages that use this system must be perfectly clean for the engine to run properly.... the air screw has a spring. a spring seat and a o-ring for sealing on it.. the screw setting starts at 1 & 1/2 turns out from lightly seated.. then set the screw in the very side of the carburetor (its the one that controls the idle speed).. once you get the machine warmed up and cleaned out.. let it idle, turn the air screw in and out SLOWLY about a 1/4 turn at a time..EACH TIME ..waiting until the idle settles and then until you reach the point the machine idles as high as possible, then turn in it 1/8 of a turn.. then set the idle speed with the "side screw" to a speed you like... good luck...thanks!!
Jul 17, 2017 |