Howdy, I am about to kill my carb. I just rebuilt the holley 4180 stock carb on my '85 f250 460 a couple weeks ago and had a ton of problems. First, i didn't set the needles right, then once i fixed them it still ran really rough and POURED out white smoke from gas. I finally found out after taking it apart about ten times that some of the o-rings on the tube that transfers fuel from the accelerator pump to the outlet right above the powervalve was leaking causing fuel to go into the powervavle and making it runs so rich. Well i fixed that and it was running really well and then today i started it to go to the store and it ran like crap. It idles fine but when you try to give it gas it hesitates then loads up and it runs like someone threw a rag down the intake unless you stand on it for a couple seconds and get it above 2000 rpm. I'm lost, i really don't know what the problem is any help would be appreciated. TIA

 

Aggie have you gone to the Holley website and looked at there trouble shooting guide? Try looking for a few of the items they mention there. One other quick question, did you soak the carb body in carb cleaner for a while? I had simialr problems with my old carb before I finally gave up and swapped it out. Some of the things I did find wrong after tearing it apart again was the needle and seat were stuck partialy open allowing the bowls to over fill and leak out the top vent tubes back into the carb... white smoke. Check to make sure you didn't cut the needle and seat o-rings or that there isn't any gunk on the needle. Also telling us that the engine runs like a rag was thrown down the intake doesn't do much for a description for me. Does it seem like the engine stumbles or wants to die like it is cool until you open the throttle to allow more air in past the idle circuit? If so check the last thing I mentioned. And lastly what kind of fuel filter are you running? There is a clear fuel filter out there that is very useful in finding out if you are sucking fine particles into the carb. The fine particles will make everything go out of whack at once. Keep that in mind and lastly Holley's can be tempermental at times.

 

Well, i took the from bowl off today and found a little piece of old gasket in one of the jets. That fixed it, runs great now. I cleaned it out pretty well, but not quite good enough i guess. Hopefully it won't happen again.