Carburetor Chaos: The Float That Nearly Ruined Race Day

I made a mistake so that you don’t have to! Let’s talk about this misadventure I had recently at the Fox Hunt race. So, the day before the race, they had a test and tune session, Which was a great time to make some tuning changes to my El Camino to better run here at lower elevation in the humidity.. I reached out to my carb guy, Mike from Velocity Racing Carbs—seriously, if you need a carburetor, this guy is the best! We decided to make a couple of changes, like advancing the ignition timing a few degrees to help cut through the humidity and leaning out the jetting a bit since my plugs were reading a little rich.

I was feeling pretty good about the changes. I put everything back together, fired up the electric fuel pump, and—no leaks! Awesome, right? But when I hit the track for my first pass, things didn’t go as planned. I experienced a major lean sag at the top of first gear, not what was supposed to happen.

Back in the pits, I started troubleshooting like a madman. I cleaned the fuel filter, double-checked the fuel pressure, and even added a pound just in case. But after another pass, the lean sag was still there. That’s when it hit me—I had completely forgotten to check the float level on the secondary side of my Holley 4150 carburetor. The primary side was perfect, but the secondary float level was barely at the bottom of the sight glass! No wonder I was having issues in first gear after launch

I raised that secondary float level all the way to the top… I could almost hear Mike gasping in disbelief over the phone when I told him what I did! But hey, sometimes you gotta take risks, right? After that adjustment, it was time to see if my El Camino would finally run like it should.

Sitting in the pits, the car revved like a champ, but I knew it needed those G-forces on launch to really test it out.It’s sometimes the simplest problems take the longest to solve. It’s easy to overlook the obvious when your mind is racing a million miles an hour!

So, remember gearheads, always check the simple things first when tuning your car. Those little details can trip you up more often than you’d think. Thanks for tuning in, and let’s get back to the garage and build something amazing!