[Gaz64]

Originally Posted by Bobcat

FWIW , I had the same ( I think ) issue on the track and on the street with my 4150 DP . Long story short ... at 2700 to 3000 rpm at light /partial throttle , you`re where the main circuit is just starting to come in and you`re still mostly on the TS and IFR ckt . What PV do you have ? Most QF carbs have a 6.5 PV .... go to a 9.5 or even a 10.5 pv and see what happens . My guess is that will cure the miss/bog as you roll into WOT. At that point , your vacuum ( as mine was ) probably is well above the 6.5 setting of the PV and you`re actually running lean because the PV hasn`t opened up yet . Don`t believe internet lore about selecting a PV by taking idle vacuum and dividing by half. Get your vacuum reading at cruise and light throttle with very little acceleration and then go under that by about 2 inches . It won`t make you rich at idle as the internet says since it is really not in the ckt at that point .
Also , check your TS setting on primary and secondary . You should have about .025" showing with the blades set for your idle speed .
You may have to play with your TS restrictor , but I`m betting that going to a 9.5 or 10.5 PV will cure it . That`s what I run on the street and track with no issues .
The best way to check your plugs ( my opinion ) is to cut the shell off with a die grinder so you can see the porcelain at the bottom . That`s where you need to read the plug .

I love others who believe this theory, and not the internet hogwash.