Technical Holley 4 BBL ID

Scored a free carb. Well free but stuck. No air horn, and very well removed if a home job. Did they come that way from Holley? 4781 on metering block. What's the best soak to free throttle plates and screws before disassembly? Corroded, not gummed up.

 

yes, some came without air horn (performace models) model number is stamped on the air horn ....if you have one. don't know where to look on your model. In Holley terms, the model # is called a list#.

 

List #4781 is an 850 double pumper I think. Best bet is to get on the holley website and check the throttle bore sizes and other measurements to verify.

 

That's a 850. Spray it down with some Gibbs or something similar.

 

Soak the throttle blades and shafts with some Kroil, its supposed to creep into a millionth of an inch space.

Here is their website - http://www.kanolabs.com/

 

Thanks for the info and advice guys.

 

If the outside is that rough, you probably need to at least pull the bowls and metering plates to see what the inside looks like. The carb has been modified, so you need to check jets/etc. to see what's been done to it and baseline the carb. 850 might be a bigger carb than you need unless your running lots of cubic inches and/or lots of rpms.

 

Usually when someone mills off the choke they also take off the ring that centers the air cleaner so yours may be a factory job. Spray it down with Gibbs or PB Blast for a few days then carefully take it apart.

 

I thought it looked factory because of the breather locating notches.