Hi Sam and welcome to Ninjette!
This is classic symptoms, thousands have been stuck here. Your carbs aren't factory-fresh clean. I assume following wasn't done:
- soak in hypersonic cleaner (+5000ghz)
- using radioactive caustic solvents
- all fuel-passages before and after jets flossed with brushes and wire
- micro soda-blasting @ 10 000psi+
- float-level set and butterflies synced
Your symptoms are exactly same as many others who've come before you with partially-cleaned carbs. But not fully restored to brand-new factory-fresh condition. Do search on here for "ducatiman clean carbs" to find others that had this problem and how they resolved it. Also there's many photos of hidden secret fuel-passages that aren't obvious.
Also may need to replace all rubber parts: O-rings in fuel-distribution tube (did you separate carbs?). O-ring in pilot-jets. And float-bowl seals along with new float-valves.
Bike will run like brand-new scalded cat off showroom-floor when carbs are factory-fresh clean.
