New carb installed, engine racing

[Redmond49]

I installed a rebuilt card from a shop this evening, and got the car running. The shop says they set the idle on a test motor at the shop, but on my engine the engine is revving full blast. I started to turn the idle screw but it was having no impact so I just shut it off because it's running really hard. I then checked that the throttle linkage is in the right position, and the choke and throttle don't appear to be hung up. They seem to be in the same positions as on my other P-15. The vacuum tube to the distributor seems tight.

Then I tried tightening the idle screw all the way in and it started fine, and ran at a bit lower RPM, but still way too fast for idle. 

 

Recommendations?

Edited October 31, 2018 by Redmond49

[HotRodTractor]

Which "idle screw" are you adjusting? The idle mixture screw - or the idle speed screw? Turning the idle mixture screw all the way in will lean out the mixture at idle. Turning the idle speed screw all the way in should increase your idle speed.

[Redmond49]

OK, tinkering with the correct screw and some additional fiddling revealed that the accelerator wasn't returning all the way to it's resting position. A new tighter spring seems to have solved the problem.