kuykw

Is the idle mixture screw the same as the "pilot screw" in the manual? The ones with the white cap on them? If so, I did try that adjusting that a good bit. For example - 1/2 turn out, 1 turn out, 2 turns out, etc. Then I would drive it around a bit, but I didn't really notice much of any improvement. Maybe I should try again. Does that screw adjust air or fuel?

Hello all- I recently purchased a 77 xs400 and the bike is in pretty good shape - only about 5,500 miles. Since getting the bike I have replaced both air filters, both spark plugs, flushed front and rear brake fluid, and taken apart the carbs and cleaned them. For the carbs it was the first time I have attempted anything like this so I took it pretty easy and didn't take absolutely everything apart. I originally decided to take the carbs apart because I was noticing that one (right side when sitting on the bike) cylinder was running too rich. I was hoping that taking the carbs apart and checking/fixing any obvious problems would do the trick. But no such luck. Same problems again when I put everything back together. Anyway, it only seems to run rich at no more than 1/4 throttle. When riding I can feel the bike running rich when starting off from a stop, but after that 1/4 or so throttle the bike kicks in and feels strong again. I can see the sooty, black residue on the spark plug when I take it out after riding. Any ideas on the specific problem before I take things apart again? Could it be something other than the carbs? Thanks, Will