Topic: Needle jets and mid throttle adjustment 1974 CH750

[Sams Cycle]

Mid range jetting. I have a nice restored 1974 CB750k4 that runs very lien at mid range only. The carbs are OEM.
The engine is sound with 175 psi all 4
I raised the needles all the way up by dropping the cir-clips and still the same.
putting washers under the needle clips won’t work because the slide holders tighten flush to the clips.
It idles perfect and once I get it past mid range It opens up nice on the 140 main jets.
It has 4 high flow K&N air filters and
almost no back pressure in the very loud exhaust.
Other than restricting the air intake does anyone know of needles or a jet kit that comes with richer needles?
Thanks for any suggestions.

[slikwilli420]

Something else not right here. 140 mains and needles all the way up is very aggressive jetting. I am running an open pipe and stacks on my stock motor race bike and running 120-125 jets in there, with basically stock settings on other circuits. Go back to stock carb settings and start again. You should not be THAT lean with that much fuel.