I have a chance to pick up this carb for next to nothing. Holley List # 4777-2..... 3138 Its a 650 double pumper I believe. I have a new 650 speed demon vacuum secondary that I haven't put on yet. I have never rebuilt a carb but would like to try. This carb has been sitting on the shelf dry and dusty for a few years. I assume it would need a complete rebuild. How much is involved as far as parts that would be needed? If I rebuild it , it would be nice to compare the demon and this on my baby.

You can go here http://www.holley.com/HiOctn/TechServ/TechInfo/FMCTech.html

and look at the exploded view of the different carbs they list to see wich one is comparable to yours to give you an idea of what you'll be seeing.Rebuild kits from the auto parts store run $15-20 bucks and come with a diagram breakdown for your carb as well as the all the factory settings.........

Go for it- with hardly any cash in it, it will at least be a learning experience..

Holleys are incredibly easy to work on. The hardest part will be getting it apart unless it has non-stick gaskets. Which you should use to put it together. Be sure to clean the old gasket material off. Something to watch for is warpage in the base plate, base plate to body, and body to metering block surfaces. Have fun smile.gif

Check out Holley's web site. It has exploded diagrams and a listing of tech info by model number (jet sizes, rebuild kit part numbers, etc.) There are a couple of different levels of rebuild kits available. The Trickit packages are universal (4150/4160, mechanical/vacuum secondary, side/center hung floats) and come with a ton of parts. Just make sure to note, layout, and/or photo the parts you take off the old carb, because there are a lot of extra parts in the kit. I suggest dipping the carb in a good cleaner (available by the gallon at parts stores), then spraying clean with aerosol carb cleaner.