View single post by Esprit2
 Posted: 01-25-2022 08:01 pm
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Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 572
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Paul,

Back in message #12, you wrote that the fuel pressure was 6 psi. Is that still true, or have you installed an inline fuel pressure regultor and dialed the pressure down?

The pressure at the carb inlets should be 1.5-3.0 psi.
I use an inline regulator set to 2.5 psi.
Do not exceed 3.0 psi at the carb inlets.

6.0 psi will over-power the float-controlled inlet valve, and force too much fuel into the float bowls.

If the fuel pressure is still 6.0 psi, then install an inline fuel pressure regulator, and get the pressure 'at the carb inlets' dialed down to ~2.5 psi.

*~*~*
In that same msg #12, you stated the float weight was 10 grams, and the float height was 16.5mm. Is that still the case?

*~*~*
With the Main Jet assemblies (the brass sticks) removed, look down into the jet wells (the open holes), and you can see the surface of the fuel pool. The question is, how far is it from the top/ rim of the jet well to the surface of the fuel pool. It should be 25mm regardless of the floats used. Heavy floats set deeper, or lighter floats set higher... each float weight/height combination should result in the same fuel LEVEL... 25mm. What is the fuel level in your carbs? Run the electric fuel pump until you hear it slow a bit, indicating the float bowl is as full as it's going to get. Then switch off the pump, and measure the fuel level in the main jet well.

If the fuel pressure is really 6.0 psi, then I suspect that the fuel level is too high. If 25mm is corrrect, then a smaller number (like, 24) is higher. Higher is richer, and may be why your engine bogs down... it's flooding out.

Regards,
Tim Engel