Having finished my Dresda 500 I'm trying to get it running well. Have experienced a problem whereby the bike starts on choke, In warming, it initially runs on no choke but after a while coughs and then stops running. Leave it for a while and this repeats. We hooked up an exhaust gas mixture probe and what happens is that on choke it has the correct mixture for normal running, is too lean when the choke is opened but then the exhaust just gets leaner and leaner and eventually gets so lean it doesn't run. The fuel supply is from an elevated tank and the fuel lines run fine.
This happens with the engine on tickover but it seems not to happen when the throttle is opened into the area where it is running on the main jet not the slow running jet. On my brit bikes I'd look at checking the slow running jets and perhaps raising the needle a notch but I'm not sure with these carbs but I have them off the bike now and will check the jets. Any thoughts on this lean issue, especially why it would just keep on leaning out and stopping. The obvious thought is fuel starvation but the supply seems good.