stalls out at full throttle

i have a 1997 chaparral that i just had a 98 volvo penta 5.7L motor put in runs fine up to half throttle pass that and it feels like it falls on it face it stalls out...i was told it had something to do with the carb. it hads a rebuilt 4bbl quadrajet is what i was told...

Jason,
I too am experiencing the same issue. Hoping someone will chime in. Thus far, I've rebuilt the carb (thought maybe it had something to do with the accelerator pump or float) and also replaced the fuel pump with no success. I can troll all day on this motor, but as soon as I open it up, it dies (no high rev sound right before it dies, so I no longer think it's a fuel related issue). Removed my distributor cap and the ignition module is pretty corroded, so hoping to clean it up and double check the air gap of the sending unit (.08" is what it should be from what I've seen... for my distributor, Volvo pn 3854077). Bought new wires, cap, rotor and plugs. Hoping to get them on this coming weekend.

mine hasnt died yet it just acts like it is getting to much fuel r not enought fuel i was told to make sure my back carb flaps r opening and double check my timing..but i did not think about the dis..i will check that as well..but yea hopefully someone knows what is going on..

Here are a few simple things to do to help pinpoint the problem:

1. Disconnect (and plug) your main fuel line. Bypass the main tank with a jerry jug. This shall rule out problems with siphon valves, restricted filters, lines, etc.
2. With the engine off, place the shifter to WOT. Remove the flame arrestor and ensure the butterfly plates in the carb are fully open.
3. Inspect all wires. Ensure wires are not grounding out.
4. Pull plugs. Inspect. Are they oily, carboned up, white, orange, wet with fuel?
5. Check ignition timing at idle.
6. Check vacuum at idle.

Start here and post your findings. It is usually something simple.

Perhaps your flame arrester is restricting air flow to the carbuerator at wide open throttle.

Are you getting proper advance? Make sure you're achieving TA. Check your manual for TA specs. Just checking base timing is nto good enough; doesn't tell you whether your advance is working as it should.

I had a similar issue, it turns out my low pressure fuel pump ( the one on top of the fuel filter) died. It is the one that sucks the gas from the fuel tank and delivers it to the high pressure fuel pump; which is the one that feeds the carburetor. The high pressure fuel pump cannot pump enough fuel all the way from the tank to deliver to the engine. That's why I was able to idle, but nothing else.

To test the low pressure fuel pump get a 9 volt battery and hook it up to the leads of the fuel pump, you should here it spinning if it works.