Balancing Banks

Was always used to using carb sync. for multi-carbs but for CIS, the air filter box inlets are too large for syncs to mount to w/o having to fabricate adapters. So I T'd off the vacuum port of the exhaust cam covers & hooked a vacuum gauge to ea. bank simultaneously and got a fluctuating reading of 17-17.5 after adjusting the large hex socket screws @ throttle bodies (a little @ a time).....is this about where they should be?
Also discovered that the CIS richness adjuster is very sensitive, a very slight twist would throw the CO reading off by 0.5%. The motor purrs @ 2.0 %, didn't seem to like it down @ 1.5% level, wasn't idling as smooth.

 

The factory calls for 1 to 2% CO.
Mine also runs better around 2%

 

I thought yours was set @ 1.6%, it just wasn't settling in for me there. And besides, I discovered a lean bank when I swapped out the plugs so I thought rich is safer than lean.

 

I cut it back to 1.5% and it just didn't seem as strong.
She's back to 2%