Finally got the XRR carb on the XRL. It has a 65 pilot, 165 main with fuel screw 2 turns out. I am at seal level (Houston). Carb is clean as a whistle. I couldn't get it to run except with the choke on (lever up). It will die as soon as i turn the choke off (lever down). When running it will stumble at 1/4 throttle. What could be the issue? I checked for air leaks by spraying carb cleaner on the manifolds but didnt notice any change in idle. It's a pain to remove and re-install the carb as it is. Hmm, maybe one of your vaccum lines/over flow vent tubes are pluged or hooked up wrong. If that's not it go to a 68s slow jet and see if that helps.