MORE CARB ISSUES PROFORM 850 DP

Fuel and Air Systems

  1. Frankb

    Frankb Well-Known Member

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    I've been having problems with my Proform 850 racing (no choke) series carb. Its been on the car for about 7 years but only has about 1500 miles on it. I've had some issues a few months ago and got all but one problem fixed. Fuel discharges from the secondary boosters when fuel pressure is applied. When I take the bowl off and apply air pressure and manually lift the float the air stops. Valve and seat look good. I'm going to assume float level is still good. Its never been adjusted. I know I should assume nothing but with fuel pressure applied when carb is on the engine gas is just being pumped into the manifold and into the engine. Should I just replace the needle and seat assembly anyway?
     
  2. Jeremiah

    Jeremiah FBBO Gold Member FBBO Gold Member

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    Make aure the float floats.
     
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    • 65-440

      65-440 Well-Known Member

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      YES !!!! But also, where is it dumping into the engine from, bowl vent or squirter ? Is the pendulum there underneath the squirter ?
       
    • Frankb

      Frankb Well-Known Member

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      The float is good. I submerged it for 10 minutes and compared the before and after weights. 302 G before and after. Fuel is dumping from the secondary boosters, not the squirter. Whats the pendulum?
       
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      • 65-440

        65-440 Well-Known Member

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        The pendulum is underneath the squirters. Without it fuel would constantly dribble out of the squirter nozzles.... sure you don't have too much fuel pressure?
         
      • Frankb

        Frankb Well-Known Member

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        I didn't check pressure but primary side is good. Fuel is not coming from the pendulum. There is a hole in each booster and its discharging in equal amounts from each booster. I think I'm just going to buy a kit and go through the carb. Thanks for your help.
        Frank
         
      • RemCharger

        RemCharger Well-Known Member

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        7 years is time to chuck a fresh kit in. Sometimes the needle oring rots out. Take a good look at the tiny emulsion holes in the metering blocks.
         
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        • 65-440

          65-440 Well-Known Member

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          True, high pressure would affect both sides. Tear it down and clean it out !
           
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