Bob Z. said:Can you give the slide # and main jet numbers also the needle ring info?
Are you using 30mm Amals? I also want to try Concentrics on an Atlas
BillT said:The P11, which is an Atlas motor in a Matchless chassis, used concentrics and a distributor. The original specs for the carbs were wrong, though. The specs originally called for 250 mains, 270 without air cleaner, 107 needle jet and #3 slide.
The set-up should be:
930 carbs
200 main jet
106 needle jet, middle notch
#3 slide
You have to file down the dummy side of the boss for the idle set screw on each carburetor for them to fit. Atlas carbs are set a little closer together than Commando carbs