Carburetor Problems?

[Broadebean]

Hello,

needing some help with my Jeep YJ 1988 4.2 model that I have and a bit confused to which carburetor is installed on my jeep? Original or another model I will attach some images, it seems to be running lean with some burbling noises coming from the exhaust with perhaps a late timing from what I have read, I’m not very experienced on carburetors or YJs for that matter, and maybe someone could help explain how to set correct timing and carb settings.. I can’t seem to find the mixture screw if indeed it has one! Also when accelerating there is some knocking sound as if there isn’t enough fuel getting through, sometimes it will stall if revs aren’t high enough so have adjusted the acceleration screw on the carburetor with it idling at about 750, when accelerated though it does have a second or so staying in a higher rev and then lowering itself if that makes sense I shall try and add a video I took of the drive.
maybe also a vacuum problem… all help would be much appreciated!

cheers

Max

 

[Gilaguy23]

Id say that's not the original carb as I see a part number sticker still after 30 years?, as well as capped vac lines. Not necessarily a bad thing and that's how you get a rebuilt sometimes with a few unknown nipples on it, but these carbs are not known to be exactly problem free or good running. The line with a bolt in it by the PCV valve might be a tank vent line that should be corrected ,but Its hard to tell without tracking things back to where they go. In the vid its hard to tell what the noise is other than a rattle of some sort. I was expecting to hear a rod knock or lifter tick but its surely not the case. Your gonna need a timing light to time it correctly or have a shop do it. Id be checking for vacuum leaks around the carb, make sure the carb upper and lower halves screws are tight as well as the base bolts. Check the manifold gasket for intake leaks, and that the brake booster diaphragm isn't shot. Its s a start anyhow. If it were mine Id install a Howell FI kit and shitcan all those vacuum lines and smog line spaghetti.