Buckminster
XS650 Member
My 1975 xs650b is getting real close to running well. I just worked my way through most of a major tune-up and it still is running a bit rougher than I'd like. I'm wondering about the fuel/air mix screw setting on the original B38 carbs. The original manual calls for "1 3/4 turn" while all the other specs for this bike (that I have found on line) call for a 3/4 turn. Maybe the manual is saying (1) 3/4" turn? Anyhew, It does seem to run better with 1 3/4 turns and begins to backfire and bog-down at 3/4 turns, but that seems like a big difference and I'd rather not burn something up running it lean. Does anybody have any knowledge on the issue?