Just wanted to find out if any one had any ideas on why my 750 Dp holley carb keeps overflowing the bowl in the front, When the front bowl is off the float moves freely and it seems the needle goes into the seat properly, Thinking there might be a problem in the seat I replaced it with a new needle and seat, then also put in a new float but the same problem ,I set the float level to where it should be at the bottom of the sight glass as a starting point, but the fuel starts going in and goes over the top of the float until it is flowing out the top of the carb. the float needle and seat move freely before it is installed but then it acts like the float doesnt want to move as the fuel rises, I am out of ideas after replacing needle seat and float,

Just letting any one know that the float problem is fixed, I tried another tin float which didnt work and then went and tried the nitrofil or a black plastic float and it worked fine with that float but after 3 of the stock style floats I still dont know why the factory one wont work and the plastic one does,

Take the old float and put it in a cup of water. It will probably sink! The tin floats are known to be leakers as the seam between the two halfs are soldered together. Push the float under the water and see if any bubbles appear. The nitrophyl floats are good as long as the skin isn't disturbed. These floats are also affected by certain race fuels and alcohol.

They're also affected by most of the so-called "octane boosters", which are LOADED with alcohol (which also eats the plating off the inside of the float bowls, then the alcohol attracts water, which attacks the now-unprotected float bowl surfaces). :eek: