Volvo Penta 3.0 stalling issues

[adamkat22]

Working on a 2001 Volvo penta 3.0GSPA that sat for many years before I acquired it. Syphoned out the old gas. Put in fresh gas, seafoam, spark plugs, fuel filter, etc.
First day ran great, but only ran at low rpm’s because I couldn’t get out to somewhere where we could open it up

A month later took it out again. Was hard to start but then trolled around just fine for an hour (also at low speeds)

Third time out was starting to hiccup a little. Went harder with the seam foam and topped off with fresh gas (also at low rpm’s the whole time)

Today was the first day I was actually able to get somewhere where i could get to WOT, and it stalled within a minut or so of being on plane. Then all the way back it kept stalling (at idle and at WOT) and became harder and harder to even start it. Symptoms are as if it’s starved for gas (ie is slowly sputters out)

I’m assuming carb rebuild is the next thing to do? Is there a simpler low hanging fruit?

 

[dubs283]

Sat for many years, like more than 5?

It's good you removed the old fuel. Guessing there is remnants of old fuel stuck around in the tank and it's now come loose and is clogging the fuel supply system possibly up to the carburetor

Inspect the tank, look for dark areas/debris or other stuff. Check the fuel pickup and anti siphon valve for blockage/operation. Fuel lines can break down over time as well

Check the filters for nasties too

No need to add any conditioners to the fuel system. The engine is designed to only run on clean, fresh gasoline. A decent quality fuel stabilizer is the only additive you should introduce to the fuel system

 

[adamkat22]

I know the boat sat for at least two years…but I’m guessing it actually sat longer. We replaced the anti-siphon valve, inspected the pick up foot, made sure the vent line was clear (the one up to the filler neck), and replaced the fuel filter again (this time with a paper filter instead of the stone one).

Still doesn’t want to run at more then just a minute or so on plane before it bogs down and eventually stalls (unless you throttle down to idle).

Is the carb the next thing to investigate? I know it’s a Holley two barrel carb but don’t know anything else . Anyone know how I can figure out what model carb it is so I can do some research and order a rebuild kit?

Anything else we should try first?
Thanks!

 

[alldodge]

Having different issues all concerning the carb it would be time to rebuild. Holley's are pretty easy to do, getting them real clean is the hardest part

VP kit 2153394

Should probably get the similar kit from Mike's Carbs on line

 

[adamkat22]

Just to update and close out this thread…ends up there was a stone filter (where the fuel line enters the carb) that was totally filled with junK. I didn’t realize there were any filters past the fuel pump…but once that was cleaned up all was good. Thanks for everyone’s help