the supertiger carb is a bit different than other carbs.the two needle version has an interaction between the two needles.it is possible that the low speed needle is turned in too much so that the high speed needle can not richen the mixture.the sparay bar in the supetigre uses an elongated slot the low speed needle should not extend beyond the middle of the slot.usually to do a proper setup the loe speed needle is turned to the richest setting and then the high speed needle is set for max rpm with and backed off about 1/8 turn or so,then you lean out the low speed needle for a reliable idle a little at a time,the first few times you go idle expect the engine to die as it floods out,just close the low spped needle 1/2 turn at a time till it stays running so you can fine tune the low speed with the engine running,then recheck the high speed setting.