Hitatchi HSC32 Carb wizardry

Quick question for the brains trust. with the intake butterfly closed, should it be a completely airtight seal?
I have a very technical testing methodology for this. Seal intake around mouth and blow. Some of mine seem to be more airtight than others. Carbs have been rebuilt and butterflys are 100% from the carbs they came out of.

 

I’m no expert, so I may be corrected, but:

no, the butterflies should not be air tight. They need to have a little bit of airflow to run. The trick is to synchronize them with their cylinder and the other four carbs and cylinders.

the bench synch can be performed with a business card or paper clip or something to make sure they are slightly open the same amount after a rebuild or something. After the bench synch you need to do the running synch to compensate for variations in the cylinders.

but the goal is definitely not a to have them air tight at idle

 

Thanks Dan, Thats what I had kind of assumed. There would need to be some air getting through.
yep, not at the synch stage yet. still have a whole lotta building first.

 

There's a good write-up on this on the tech section. Click on the XJ4Ever banner on the top right and go down to the Church Of Clean.