Carburetor Drilled Return Pressure Balancing Modification GPR, XLT, GP, SUV, etc.

[AM116]

I'm sure this is a dumb question but I have tendency to screw things up so just want make sure I have this correct.

For this mod basically just need to drill out the return orifices with 1/8" bit, then on the #1 carb return line nipple, just tap it with M5 and install 95 main jet (I have 2001 XLT) and then slide the return line over the nipple with the jet install and bingo bango you're done?

[Cutlass]

I'm sure this is a dumb question but I have tendency to screw things up so just want make sure I have this correct.

For this mod basically just need to drill out the return orifices with 1/8" bit, then on the #1 carb return line nipple, just tap it with M5 and install 95 main jet (I have 2001 XLT) and then slide the return line over the nipple with the jet install and bingo bango you're done?

Yes, that sounds exactly right.

[Ratrace]

what size restricter would i use on a LS2000. Thanks

[Mpeavler]

95

[Robb235]

95

Wouldn't the LS2000, which uses the non-PV 1200 motors, need the 105 main jet as the restrictor?

[Mpeavler]

Personally I’m not a fan of this mod if you maintain your carbs and refresh them every three years you will have no problems . You can start with the 95 and measure your fuel pressure wide-open and see where it’s at you can start with the 95 and measure your fuel pressure wide-open and see where it’s at but .

[butterbean_29512]

Its what ELSE this mod does that makes it a must do. It splits and shares the fuel flow between the carb rack, and if one fuel pump craps out the other two can supply the carb with the bad fuel pump.

[Mpeavler]

Wrong .., this simply opens up the return orffices that are typically very small and changes the location of the restriction. This mod is past the fuel pump check valve section of the SBN and they will not process the fuel in that manner . The return portion of the carbs have check valves to prevent this .

[Cutlass]

Without the restriction in the carb, the return fitting and hoses should be pressurized and the other carbs should be able to pump/back flow into the carb through the return.

[Robb235]

Wrong .., this simply opens up the return orffices that are typically very small and changes the location of the restriction. This mod is past the fuel pump check valve section of the SBN and they will not process the fuel in that manner . The return portion of the carbs have check valves to prevent this .

Your post is in direct contradiction to what Osidebill has explained about this mod in the past.

[Mpeavler]

Your post is in direct contradiction to what Osidebill has explained about this mod in the past.

Look at a flow chart for a SBN carb

[Mpeavler]

Your post is in direct contradiction to what Osidebill has explained about this mod in the past.

Look at a flow chart for a SBN carb

[Robb235]

Wrong .., this simply opens up the return orffices that are typically very small and changes the location of the restriction. This mod is past the fuel pump check valve section of the SBN and they will not process the fuel in that manner . The return portion of the carbs have check valves to prevent this .

Your post is in direct contradiction to what Osidebill has explained about this mod in the past.

[Adam]

No , if one fuel pump check valve fails the drilled out hole allows fuel pressure from the returns of the other carbs to keep fuel pressure in the failed fuel pump . That is the other advantage of this mod .

[Mpeavler]

Let’s crease one of your check valves Adam and test this theory , care to do it ??