k i have been trying to figure out all about holley carbs on the board for some time now. i have learned alot but just cant find one simple answer to something. how do u adjust a holley vacume secondary carb to have more power off the line. (what do i need to adjust) ANYONE????????????please

 

The only thing you can do besides basic tuning stuff- jet changes, accelerator pump cam and squirter changes is to change the secondary vacuum spring. It determines how quickly the secondaries open. Stock they come with a "plain" spring which is usually a bit too stiff for maximum power as the motor revs through it's range. Might try a "yellow" spring instead- I have found it to work well in almost all cases.

Note: this requires taking the secondary vacuum assy. off the side of the carb, taking the lid off, replacing the spring inside and reinstalling it, making sure all the gaskets are still sealing up (VERY IMPORTANT!). If you're going to go to all this trouble you might as well buy a $20 "quick change" kit. Allows you to do any future spring changes without removing the whole assembly.

However, as I mentioned above, these vacuum assys. are VERY touchy suckers. It's super easy to get the diaphragm installed wrong, cockeyed, wrinkled, imporperly indexed to the housing, or forget to replace the tiny gasket between the vacuum assy and the main body of the carb. In other words, if you don't take your time and be SUPER **** about it's reassembly there's a good chance you will get a vacuum leak and then the seondaries will NEVER open. Also, when disassembling there is a small ball bearing in the vacuum passage under the lid- DON'T LOSE IT AND DON'T REMOVE IT. It's critical to the proper operation of the unit.

 

no i dont mean that i dont have the power that i should have my secondarys r slow or something and it should have more power off the line. what to i play with to adjust my secondarys?