Well I really did it this time. :bonk:I can't figure out what I did but the bike is running like crap at cruise. Idle is fine, WOT is fine but it stumbles and surges at mid range and my AFR meter is showing around 16. I have had the carb apart 4 times, completely stripped it and can find nothing wrong. The bike is almost unusable now I have to pull the choke on to limp home. It all started when I pulled the carb off Thursday Night to take measurements (planning an EFI project). While I had the carb off I decided to pop in a DJ 160 main (been running a 155) for a quick test. I didn't touch the needle. When I took it for a ride, the idle was good with AFR around hi 12's to low 13's. WOT looked good, with mid to high 12's. Any time accelerating moderate to hard it is fine. But WAY lean at cruise! And this with the exact same needle setting I have been running for weeks! I have been running the DJ needle with the clip in the second slot. AFR readings have been mid 13's for 5th gear cruise. The bike set up is, open air box (4 1" holes), ground headed weld, DJ needle, DJ 155 Main. Wideband O2 sensor and AFR meter. So I went back to the original main and checked everything. No Change. I dropped the needle clip to the 4th slot. Better but still too way too lean. Tried 5th slot. Still a little lean at cruise and way too rich just above idle and low speed cruise. Like 10 to 11 on the meter. Pulled apart again and remove the needle jet. Could not see any issues. Checked the float. OK. checked the manifold for possible leaks. Gave up and put all back together. Same problem. I sprayed WD-40 around the carb while it was running to try to detect leaks. Nothing. So anyone have an ideas?