Motor bogs and dies under load/acceleration

[Bear Laker 72]

Hello fellow boat adventurers.
I recently bought a 1973 Gulfstream with a 165 HP Mercruiser inline 6 GM 250 set up.
After a minor tune up, it had been running perfectly other than I think it ran a little rich.
After about 6-7 days out on the lake, last weekend after problem free cruising around all day, I was taking friends back to the shore and all of a sudden when I hit the throttle while in gear it would bog down and kill out when trying to bring it up to speed. It worked well enough to get back to the boat ramp at low speed and load up but just can't figure out where to start to diagnose it. When in neutral, it revs up fine but only bogs and cuts out under load.
I was planning on taking a look at it this weekend and I have decent mechanic skills but it's been a while since I've owned anything with a carburetor. (It has a 2 Barrel Rochester in it now without and electric choke BTW)
Any advice?

Thanks in advance!

 

[Bondo]

Hello fellow boat adventurers.
I recently bought a 1973 Gulfstream with a 165 HP Mercruiser inline 6 GM 250 set up.
After a minor tune up, it had been running perfectly other than I think it ran a little rich.
After about 6-7 days out on the lake, last weekend after problem free cruising around all day, I was taking friends back to the shore and all of a sudden when I hit the throttle while in gear it would bog down and kill out when trying to bring it up to speed. It worked well enough to get back to the boat ramp at low speed and load up but just can't figure out where to start to diagnose it. When in neutral, it revs up fine but only bogs and cuts out under load.
I was planning on taking a look at it this weekend and I have decent mechanic skills but it's been a while since I've owned anything with a carburetor. (It has a 2 Barrel Rochester in it now without and electric choke BTW)
Any advice?

Thanks in advance!

Ayuh,..... Welcome Aboard,...... It's a 99% chance, that ya got a fuel delivery issue,.....

If ya don't already have a sep/ fuel filter 'tween the tank, 'n fuel pump,....
Ya oughta add one,.... not only do they keep water, 'n crap outa yer motor, they're a Great diagnostic tool in cases like this,.....
'n you'll never ever have to change out the fuel pump, 'n carb mounted filters,....