Benny,
Sorry, a little slow on the follow up. But, yes, running a little on the rich side is way better than the lean side. The richness will cause the plugs to be a little darker, burn more fuel but it also keeps the motor a tad cooler. Not a big deal unless it gets too rich, kind of a fine line there.
With my current setup; freak/160 mains/42 pilots/Tbike pipes /TBS needles it is a tiny bit too rich. The Thruxton needles would necessitate dropping the mains down about 3-4 steps due to the big increase in WOT fuel from the Thrux needles (even more taper and fuel flow than the TBS needles).
The better taper will increase the fuel flow at the WOT point which is also the same as the mains jets.
Now, After I do the Big bore I will most deffinetly use the Thruxton needles and drop the mains down to about 130's again. Then do some plug checks and some dyno runs after a breakin period.
I'll keep ya posted.
