I have a new BST CV 34 that was jetted out for a 330 trail boss. I opened it up to swap out the jets to a 425 setup and decided to have a look at the numbers and taper on the jet needle. The needle jet is a "P-4" with 10 holes while the 425’s needle jet is the P-8 with 6 holes. I have spent the better part of a full day trying to ID this P-4 and what it is supposed to go in because the listings I have found say that the P-8 goes into both carb setups as mentioned. Now the jet needles are way different as well. The taper on the P-4’s jet needle is almost non existent while the taper on the P-8 is clear to see. So the big question is do the extra 4 holes in the P-4 needle jet combined with the all but straight jet needle compensate for the fuel flow versus the P-8’s design as mentioned making them equal in overall fuel flow? :hmmm: