Merc 3.0L two stroke 225 hp

When i picked up the boat last fall it wasn't running very good. it had sat for a year so i figured there were some fuel issues. it would run around 4500 rpm and 30mph WOT. cleaned and rebuilt carbs and replaced the fuel lines bulb and filters and rebuilt the pulse pump. now it will only idle for a bit then dies. it acts like the fuel pump isn't working. i can pump the bulb and get it to run for maybe 30 seconds. then it tries to fire but will only run for a few seconds. if i pump the bulb too much it will start dumping fuel out of the carbs.

i have run the following diagnostics:

compression - 70 ish on all cylinders with crappy HF gauge. i have a better gauge but need to charge the batteries. will check when the batteries are charged.
leak down - minimal loss on all cylinders up to 80 psi

link and sync
replaced fuel lines, primer bulb, filters
rebuilt pulse pump
clean (spray and poke with little brushes and dry with compressed air) and rebuilt carbs (needle and seat) and re-jetted for elevation 6000'

check spark with timing light and spark tester on all cylinders

calibrate TPS

also run off remote fuel tank same results

I'm thinking my next step is to get a clear fuel line between the inline filter and #1 carb to check for fuel flow. any other thoughts?