i threw the 34mm on my stockish motor just to get it semi tuned, so when my engine came back from getting ported by ken oconnor racing, i wouldnt have to risk my engine to an untuned, untested carb.
i prolly only had it on there for the pilot and needle adjustments and possibly a very rich main jet, just so i knew it started, idled and ran before i pulled my top end, so when i got it back, i knew it would start and idle for my heat cycles and low/mid throttle break-in.
i already had my trinity pipe, VF3's, CFM airbox and uni filter. i did not run the bike hard if at all with the 34mm before getting it dailed in on the new porting.
so i cannot tell ya for sure what difference it made on the unported engine ?
but facts show you'll gain some mids and huge top end gains, at the cost of a little bottom end.
my jetting then.....
45 pilot
airscrew under 2 turns out for highest idle
a DGH needle < a must have, or CEL for lower elevations than my 1800+ feet
and a 155 main jet/ 162 for temps under 50 to 30's
since my last round of porting i had to jump to a 48 pilot