Butterfly valve

so I recently had to replace one of my butterfly valve on my xj550. Now there is play in the valve. I can push the top half of the valve and it will move backwards and when I push on the bottom half of the valve it moves back forward. Any idea what part I need to replace now? All the other carbs are tight like they should be.

 

Sounds like it may be out of alignment, and that would obviously give you hell while trying to adjust/sync. Try to loosen the two screws and move the butterfly slightly for a better fit. then slowly snug up the screws (probably use locktite if you have some handy).

Have you replaced the throttle shaft seals? that can be a cause for slop as well, unless the shafts have worn down on the carb body itself.

 

I'm thinking I'm gonna replace the whole shaft. Because the whole shaft moves

 

It is normal to have some movement in the throttle shaft when it is full open. It should not move when closed. You need to align the butterfly in the bore before tightening the screws. Do this by loosening the screws and opening the throttle and let it snap closed, this will center the plate. Do this several times then tighten the screws while it is closed. The carb really needs to be separated from the rack to do this right. It won't work well if it can't close all the way.

 

+1 on the butterfly not being aligned.