BX14 1988 suitcase 150 engine carb problem HELP!!

[Bx14]

Recent brought this, I’m a 27year old mechanic and carbs are way before my time.

Believe it’s a solex 34 carb!

Starts and idles as should, RPM maybe a little low but runs fine, slowly revving the engine it will rev up, soon as you move the throttle too quick it splutters, then catches its self then will rev with a little hesitation.

If the choke is about half way out it seems to rev fine, I suspect there’s some tuning or blockage, I’ve have the carb apart and cleaned, new plugs and fresh fuel!

Any help would be appreciated, sorry if this is dumb!