bought a 70 lemans with a 350, previous owner had a Edelbrock intake and carb put on , checking the timing a found the vacuum advance wasn't connected , checking the carb I found 1 idle screw out 2 turns the other less than 1, I turned them both out 1 turn, seems good so went another half turn didnt like that so back to 1 turn, just seems it be lean don't know this carb what is the starting point for idle? thanks

On 6/12/2025 at 5:59 AM, hdbob5454 said:

bought a 70 lemans with a 350, previous owner had a Edelbrock intake and carb put on , checking the timing a found the vacuum advance wasn't connected , checking the carb I found 1 idle screw out 2 turns the other less than 1, I turned them both out 1 turn, seems good so went another half turn didnt like that so back to 1 turn, just seems it be lean don't know this carb what is the starting point for idle? thanks

Hey there,

I've just seen your post.

Edelbrock are very different to how you would usually set up carbs (Holley, QJet, etc). Many don't like them, but I put one on my 389/400 rebuild & have been very happy with it.

Look up the Edelbrock website, & you should be able to find the manual for your model. To set them up according to Edelbrock, you tune them using changes in your engine RPM. The 2 screws you're referring to (affect idle circuit only) are set in exactly the same manner; first one, the other. You'll find when correctly adjusted they are both very close to each other in position (the final setting is only asking for +20rpm, so quite delicate!).
If you need to alter how it accelerates or cruises, you need to look at your accelerator pump settings or your jets. Again, Edelbrock have very comprehensive guides to help you with this.

Good luck - hope this helps.

thanks it seems to run fine was just expecting that sudden jump when secondary would open, very happy with it I don't really beat it I just putt with the wife.