Anyone know what the float setting on an APD 4150 billet enforcer secondary should be? Have had no luck getting through their phone line the last few days. I have been setting it with the sight glass, but I would prefer to set it correctly. Thanks.

With the bowl upside down set the float so a 3/8 drill bit will slide between the top of the float and roof of the bowl. Some also set using a 7/16 drill bit, which would give a lower float level. I set mine somewhere in between around 13/32.

quote:

Originally posted by 67SS:
With the bowl upside down set the float so a 3/8 drill bit will slide between the top of the float and roof of the bowl. Some also set using a 7/16 drill bit, which would give a lower float level. I set mine somewhere in between around 13/32.

Yep. I use the 3/8 bit for reference but I like to go a flat or two lower than that.

Randy at APD told me to use a 5/16” drill bit. Good luck

not sure if any of those measurements will work. If I could figure out how to post a pic,I could show the float is much smaller than the ones I'm used to. I finally got through to somebody at APD and he said 1.004 from the top of bowl on the pump side to the perimeter line on the float. Thing is there is no line!! Arrrggh. I'll try again tomorrow or just go back to using the sight glass.

If the carburetor is a APD.

Measure from the parting line on the float to the top inside edge of the bowl and adjust it at .750. Adjust the fuel pressure at 7.0

Holly Carbs:

Holley floats are different, many don't have a parting line like the APD's. I start with a 3/8 drill bit on the primary and 13/32 for the secondary.

If the car is a hard wheelstander I first try and calm the cars landing, if that doesn't work consistently I lower the float levels one flat.

Bouncing the car / float can, and will create problems. Calming the rise and landing of the car will solve a lot of issues.

Each car/application is unique, but these recommendations are good starting points.

Bob

On an old standard 4150 rear bowl, you wanted fuel to spill over the edge, front bowl not.

Ditto on the soft landing wheelies and / or slightly adjusting the level.

Measurements are a good starting point and all, but the ONLY level that counts is at the plug or sight glass, with the pump on and the engine running .

quote:

Originally posted by Goob:

Measurements are a good starting point and all, but the ONLY level that counts is at the plug or sight glass, with the pump on and the engine running .

^^^ THIS. The drill bit or measurement gets you to a good starting point. But different floats have different bouyancy and what really matters is where the fuel level is under operating conditions. When you find the "happy place" for your front & rear float levels on your combo, write it down or mark your bowls. Then when you change floats, you can get it set back to what works.