I have a 1978 Yamaha XS400 and need the setting for the float level and the pilot air screw (number of turns). I bought a Haynes manual but it does not list the correct setting on the 2E. Does anyone have this info? - David100

If the mixture screw is on the engine side of the slide it will adjust the fuel. If it is on the airbox side it controls air. I think your is on the engine side. 3 turns out from a lightly seated position is a good starting point.

I have a 1978 Yamaha XS400 and need the setting for the float level and the pilot air screw (number of turns). I bought a Haynes manual but it does not list the correct setting on the 2E. Does anyone have this info? - David100

Hi David,

I would guess abot 1 & 3/4 turns out from home for the mixture screw, but this is subject to the bike running on idle smoothly (some xs400's needed the screw ½ turn out & others nearly 3 turns out to obtain that). With float height if the bike has not had the carbs 'played with' there is a good chance this will be correct, but I guess you have problems with the bike & it may be better to describe the faults rather than asking for specs as you may find that doing that will save you a bit of time as someone else has had the same fault in the past & has fixed it !

Regards Jim