I completed the hangar 18 mods on a 4150 600cfm carb. I however am unable to adjust my fuel level in my bowls to get low enough, I have the nut turned all the way in to the point that the brass body is below the nut and it still shoots a stream of fuel out of the vent hole in the bowls. My fuel pressure is 8-9 lbs out of a stock mechanical fuel pump.

 

8-9 psi seems high, what size needles?

 

Well 8-9 is what the chepo gauge is reading on the fuel rail so maybe I need to get a better gauge? And the gauge bounces as the engine is running.

 

The needles are what ever came from Holley on the carb. I started the Hangar 18 mods on a brand new Holley carb.

 

8-9 psi is too much fuel pressure and overunning the needle seats. Regulate it down and see if that resolves the issue.

if that doesn't do it pull the needle/seats and check for debris

 

Well I took both bowls off changed the jets took out the needle/seats and put it all back together and well I was immediately able to adjust the fuel bowls to the correct level without a problem and have 3.5 threads up into the nut. I however still cannot drive it more than 6 miles because as soon as the engine warms up to full temp the engine is choked out because it is running rich, as soon as it cools down I can start it right back up... The carb started with 66 jets in the primarys and 73 in the rear, and I could only go 2 miles before choking out. I now have 64's in the primarys and 71's in the secondarys and still WAY to rich. So I have to order another jet kit, because the one I have only goes from 64-99 jet sizes. If you can come up with any other thoughts as to why it is killing out when it gets up to operating temp let me know!

 

Does it stall, or how is the idle when it acts up? Do you have a wide band?

 

It just stalls out when it gets up to around 200* F and wont start again until about 160* engine temp and just before full temp on mid throttle 2500 rpm and then WOT 4000 rpm and shutting off the engine at those pulls and looking at the plugs they are black as coal and sooty. I do have a wideband but it is not hooked up yet.