New Zenith Carb Woes

[trguy75]

List:
This is my fist post to the community and thrilled to join. I recently purchased a 68 Series IIA 88 that was a frame off restoration back in 2000. I installed a new zenith carb as the other was giving me some problems. Choke not working and jerkiness when giving gas from a stop. The new one worked great for a few days and even the choke worked great. Now it won't idle unless choke is on. I readjusted the idle and mixture screw and it idles in the driveway fine. After driving on road when I come to a stop it stalls. Readjusted and still got same problem. Fuel looks good as I have new clear filter and fuel line from pump. This should be a simple setup. Am I missing something here.
Thanks

[printjunky]

My first guess would be getting too much air. One way to locate/diagnose is to spray some carb cleaner (or starting fluid, or similar) around the carb/intake while it's running, particularly around the seam where the top and bottom of the carb are mated (even new carbs (apparently especially new ones from India) are susceptible to the dreaded Zenith Warpage. If there is a vacuum leak, whatever you're spraying will be suck into the intake and the Rover will momentarily run differently - almost stall, stall, rev, bog, etc - depending on what/how much gets in.

Other spots where vacuum leaks are possible: any opening in the manifold (brake boost, or other vacuum lines/ports) intake gasket, throttle shaft (the shaft going through the carb on which the butterfly rotates).

[cedryck]

Good advice to check for "air gappin" a Roverphile can also use propane gas, (of course the jet is UNLIT when opperating this method), and the engine will run better when gas is pulled into the hole, (assuming of course you find it), and then run bad again when you move gas away.

[trguy75]

Thanks for the tip. I will give that a shot. I wanted to go with an old Rochester carb from a 50s Chevy pickup but couldn't find one. I heard the quality on those was much better than the new zenith carbs. I am also going to get a pressure gauge and test the fuel pressure. I really think it is in the carb.