My XS 400 runs well and has a good rev range, so that is good

I have found that if i use the side-stand that one of the carbs (Right) will drain a little making starting harder until it`s filled again when I put the bike upright.

That`s not a problem as I can use the center stand!

But no matter what I do to my bike, my idle is ALWAYS lumpy.

I have had them balanced , sonicly cleaned, new jets, diaphrams, ect, ect!

while looking at the mounts, I am thinking that the small brass tubes that are blocked off on mine should maybe be linked?? by a small length of rubber tube??

Any advise is greatfully recieved........ thyank you

one brass tube goes to the vacuum diaphram on the fuel tap.

the other has a cap.

lumpy idle is due to the pilot system mix out. need to tweek the screws to get best idle. if not sure how to do, get back on here.

Much thank you Mr D