93 Cigarette top gun, 525SC's...
warm and at idle the STBD engine starts stumbling and dies.... have to re-prime fuel pump.... pump throttle alot, it starts up, blows some dark smoke, cleans out, and runs good at higher rpm, come back down to idle and it starts stumbling and dies.
very difficult to start. repeats the cycle. Sound like a fuel pump going out? Could it be a really clogged fuel / water separator? I think its been quite some time since they were changed so i was going to start there.
Any feedback would be much appreciated. Thanks

Sounds like junk in the carb.

What do you mean reprime ? You have a mechanical fuel pump right ?

water sepetator/filter should be rrplaced each year. Dumped out 1 or 2 a year too.

i have mechanical pumps yes but secondary electronic pumps.... each side has a primer switch to charge the lines and build pressure to the gauge at the carbs...
I did earlier in the day run REALLY low on gas, started sputtering as I pulled to the gas dock but after fill up it did it again - so I agree, sounds like a good possibility of crap that got pulled up in the carb.
Odd thing is the tanks are 128 gallons but that tank only took 88 gallons, so there was gas in the tank. I picked up a couple new separators.... will put them in in the morning

Ayuh,..... Dump the old ones into a glass jar to inspect the contents for anything but clean fresh gasoline,.....

definitely was not clean gas that came out of either one of them.... lots of rusty colored sediment.
replaced, re-primed, and after it gets warm at idle it starts stumbling again and acting like its starving for fuel

Change sparking plugs while your at it in case you fouled the originals

Sounds like carb needs to be disassembled and cleaned

i called the guy that works on it the most here and he said it sounded more like I had a "carb bleeding over"... he didnt think the fuel pumps were the issue from this description.
makes sense I guess. Nickerson rebuilt them about 5 years ago, I guess its time to pull them off and send them back to be gone through again?
Sound like most reasonable course of action at this point? Thanks!

Surely the guy that works on the boat can clean out a set of holley carburetors.

Did it run the same before buying fuel?