go to tha auto store.. buy tha cheapest electric fuel pump (3 ta 7 lb output) for a carbed car motor.. connect it as close to tha tank as possible.. it can jus be hangin' free for now.. supply side of pump go straight (no bulb) to tha carb bib that feeds them all.. plug off all lines goin to and...
'bout 4 (3 @ very min.) ta 7/8 at idle.. 14 to 'bout 21 max at speed.. preferably 14/18.. gauge will show actual pressure (pump condition), any type blockage and how tha poppet is working.. theses are my opinion only and worked for many years.. you may have one of those "ya gotta be here" ta do...
https://www.youtube.com/results?search_query=rebuilding+a+WH+series+mercury+carburetor
all wh series are basically tha same as for tha way they are rebuilt.. if yours are still factory '76 models you need ta find a set of later wh series.. tha old ones still have tha "round floats" that are...
first its a 2.4.. first 2.5 was letter "d" in '91... did you jus change tha impeller?.. needs ta be a complete water pump kit.. you need a water pressure gauge ta be able to diagnose easier.. it will pretty much tell all.
no photos showin' on my computer?.. look for any small cracks on both...
second diget is letter on all of tha V6 mercs... started with A many years ago.... tha originals, 1976 till 'bout '79/'80 there 'bouts had 7 numbers.. then they changed tha first number to a letter.. then they added tha 0 in front of tha letter.. tha letters A, B, C ended with tha block change...
hard ta say from a "keyboard"???.. usually they work or they don't!.. ya might clean it up (wiring and connections, 'specially grounds) and see what it does???................
