Carb differences

ac@39 · Post by **ac@39** » Sat Apr 21, 2018 1:28 pm

Currently trying to sort out a few running issues. Have 3 sets of carbs from which I have been able to put things back to standard. However the float bowl on one set does not have the small little pipe attached to the carb drain screw. Which would be original - both are stamped 4UN and is the any function to the extra tube
Thanks

And for the curious the 3 set is 4nx with factory pros needle middle of six and tubes on 148/75 jets setup( read loads lately about these being difficult to set up so may have a play later