I tested the #53/152's, Keihin 155's, and Freeman "AB" 152.5's. All are similar, yet different.
The #53/152's were relatively slightly richer than the Keihin 155's.
The Keihin 155's were close to spot-on at WOT 7/8 throttle & up, however were on the rich side below.
Both of the above were relatively richer than the AB 152.5's.
Hmmm. What I decided to do was take a #53 4 flute reamer & give the 152.5's a few light turns, just by hand.
So far the lightly modded 152.5's perform the best overall with the current setup. The hiway cruise is sub-14, & with 3.25+ turns out on the pilot screws the warm motor idle AFR is in the low - mid 13's. I plan to lean the pilot screws slightly, & presuming there is no carb spitting, take a run to measure fuel consumption. If all goes well, I predict close to 50 MPG average, if not going WOT.
Beware of anyone who tells you that CV carbs "can never be a performance carb" or that the various carb circuts don't "overlap", as they certainly can, and do.
Mains influence far more than what some understand.
Needles are a complexity all by themselves, and needles will influence what pilot jets and screw settings your motor will need.
Float heights can make or break what you are trying to achieve.
Anyway, now to dial in the pilot screws before I focus on the vacuum piston transfer port diameter. Again.
