racecapri

I'm a newbie here but stilll stessed. I'm retrofitting a holley to a Mercuiser 350 in a 26' Bayliner. I have extensive experience with drag racing cars with holley's but this has got me stumped.
The original 90's carb what I would call a Carter 625 ABF would draw fuel through the primary boosters right from idle destroying economy. Not being able to fix that I replaced the carb with another Carter (auto) that was on hand. It worked wonderfully for a few hours and started to draw through the boosters as well. What's causing this???
Next problem now is the owner converted over to a Holley 80552 on my encouragement. Once mounted, idle and full throttle (4200 rpm) is great BUT I have no idle control on the right side of the carb, the left has some control. The carb is running a touch rich on the left side but the right is running very lean and this coresponds to the problems on the right side.
To no avail I can't fix the problem. The only thing I haven't tried was drill the throttle plates to cover-up more of the idle slot to return idle control on the right.
The owner is putting the Carter back on to quell our concern if there is any problem with the manifold, etc. Hopefully the lean-out disappears and we can continue with the Holey.
Vacuum signal and the proper PV is a little confusing with boats and the proper main jet sizing as well. There must be some tricks.

Thank you for listening. I'm quite impressed with your forum and the professionals that use it.

Racecapri (1974 if you're curious)