I have a Holly street avenger carb on a new 340 hp 350 crate motor. The carb is a 670. I am trying to adjust it and when i try to adjust the mixture screws i adjust the one on the drivers side and as i turn it clockwise to make the carb stumble and then turn it back it stops stumbling like it should.... When i do the passenger side of the carb i can turn the mixture screw all the way in and it doesnt even try to die or stumble?????????? Can anyone tell me what is going on?? Thanks
02-03-2004 03:44 PM
What manifold do you have? Sounds like a single plane and the passenger side isn't feeding anything. If it is a 180deg manifold, doesn't make sense. Best way to set those screws is by manifold vacuum. Adjust them for maximum vacuum @ the same port used for distributor advance. If the one screw doesn't affect vacuum at all, that barrel isn't functioning.
02-03-2004 05:02 PM
It is a fuel leak or something stuck in one of the passages. Take it apart and clean it well. If it needs new gaskets, get them. Clean out the air bleeds and idle feed restrictions. The problem is in the idle circuit.
Whenever a mixture screw has no effect you can count on it being one of the problems mentioned above. Holleys are extremely sensitive to dirt.
02-05-2004 07:38 AM
Thanks for all of the good advice guys, i will try them!!!!!!!!!!