83 350 runs horrid starting when cold

[CoMtGuy]

You can drill them out and use self tappers to adjust it.

Here is my adjustment sheet that has a little section on chokes. It might help.
https://www.dropbox.com/s/ht38b7uknu0yuwc/quadrajet power llc adjustments.pdf?dl=0

Thank you! I had a priority this morning, but tomorrow morning I'm working through this and the other posters advice. My carb is rich (stinky exhaust all the time), so I definitely will use the sheet. I did start leaning it out, by adjusting each side to drop 200rpm (leaning, screw in) then resetting the idle speed, one side at a time, but stopped there due to other life priorities and I was riding the motorcycle most days - but now with snow soon to fly it's time to get this carb much closer to right.

 

[CoMtGuy]

Well guys, the choke was fully closed when cold, fired up, had the nasty stumbling for a couple minutes requiring throttle management to keep running until it smoothed out after a minute or two. Checked and found about 1/4" choke plate open, fast idle was good, once warm I kicked it down and choke plate was open almost vertical.

So my rich fuelly stink problem, and the cold start stumble, is not related to the choke. I plugged off the dist vac line and closed down one idle screw at a time, one was out about 3-1/2 turns, the other 2-1/2. Here's the odd part... I turned each in until the stop and only a minor reduction in RPM, no stumble. Yes both in, completely shut, and the carb was still fueling the engine. Backed each out to 2 full turns and left them.


So the float is soaked, jacked, or something else is wrong internal. I'm about done messing with this Q-Jet, I got better things to do than turn a wrench on a carb, I see National Carb has a rebuild for $275 or so, or maybe I send it to Mark for rebuild, when I can ride the motorcycle again in the spring.

 

[rich weyand]

It sounds like the well plugs are leaking. This is a known problem, with a known solution.

Do not buy one off the shelf. There are lots of little air bleeds and such inside that are adjusted (drilled) for the vehicle/engine application. Either have Mark rebuild it, or get one built for your setup by Sean Murphy at SMI.

 

[mistaake]

Well guys, the choke was fully closed when cold, fired up, had the nasty stumbling for a couple minutes requiring throttle management to keep running until it smoothed out after a minute or two. Checked and found about 1/4" choke plate open, fast idle was good, once warm I kicked it down and choke plate was open almost vertical.

So my rich fuelly stink problem, and the cold start stumble, is not related to the choke. I plugged off the dist vac line and closed down one idle screw at a time, one was out about 3-1/2 turns, the other 2-1/2. Here's the odd part... I turned each in until the stop and only a minor reduction in RPM, no stumble. Yes both in, completely shut, and the carb was still fueling the engine. Backed each out to 2 full turns and left them.


So the float is soaked, jacked, or something else is wrong internal. I'm about done messing with this Q-Jet, I got better things to do than turn a wrench on a carb, I see National Carb has a rebuild for $275 or so, or maybe I send it to Mark for rebuild, when I can ride the motorcycle again in the spring.

Have the "quadrajet power" on this forum do it. I was gonna buy a carb from him but I ended up selling my truck... But if I ever need another quadrajet he would be my first thought. He is very knowledgeable about them.