You add powervalves it`s just going to make it richer.

these holes???

Are both carburetor setup the same? PV and jetting? If not.....

The fuel mixture looks too rich. Reduce the jetting size or increase the power valve to
a higher factor to prevent it from opening too soon.

Also, look for leaking needle and seat in carb and excessive fuel pressure.

They list as 3 circuit 1050 cfm. 3 circuit do not work well in a boat app. You can convert them to 2 circuit but I don't know how much you want to git in to.

You have Holley 9375's.. the faint stamping below the "9375" ( as though you were reading it right side up) is the date code

https://www.holley.com/products/fuel...parts/0-9375-1

Decent thread, for those that Atleast semi understand carbs, on the older list 9375’s (prob the OP’s carb) .
https://www.speed-talk.com/forum/vie...php?f=1&t=9934

hello dave,,i beleive both carbs are set up same,,guess i will add to list to check....
both motors run tooooo fat...everything on motors are same ..msd..cams ..etc...
and the PV are blocked...
so i guess i need to see what my vacum is at idle and base PV from that ...correct???
thanks for advice.........also want to get a wideband o2 senor set up.....but O2 senors can not get wet correct????
no sure where i can mount it...
thanks again

how do i change to a 2 circuit???

thanks for advice

hello speedy,,,,,the O2 sensor can not get wet , correct???
not sure if i can do that with my extension pipes,,,as they are wet.....
i guess ,,i could make them dry dump water out another way ,,,but would the exhaust extensions and tail pieces in transom get to hot????

unless i make new extension pipes and make them like headers...double walled...that would be a fun welding challenge

thanks for advice

no it cant get wet, if your tail pipes are not jacketed you cant add bungs in them