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Q: WHEN I ACCELERTE FROM A STOP ITS FINE IT LEAVES BUT ONCE IM GOING 45 MPH IT BOGGS DOWN AND WONT ACCELARATE

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I have an old classic pick up 1952 International. L110. It has a 350 Pontiac engine 4.9 with a carter 4bbl carb. I drive only for local cruises. I can accelerate fine but once I have going approx 45-50 mPH I try to step on gas to keep momentum and engine boggs down. I can then also slam on gas to open all 4bbl and same thing. only RPM sound higher but the vehicle wont move. I have tried moving the fuel mixture screws and it helps a little but I still dont get all the HP that the engine can do. any ideas?
My car has an automatic transmission.

Hi there. What you are describing is very common with either a vacuum leak, or an issue with the jetting in the carburetor. Most of the time, a bogging issue is caused by too much fuel (or a rich situation). This is typically controlled by the main jets in the carburetor. It is also possible that you have a dirty fuel filter or a fuel pump that is not working as well as it should be. Check these components to see if it clears up. If not, you might want to have a performance shop or professional mobile mechanic come to your location to try and diagnose and resolve this problem.

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