I have seen posted on here that people recomend using a 400ex carb on a 250x is that really true? I just bought on ebay a 400ex carb with stage 2 jetting. Will this be to much carb for my 250x? Also the seller stated something about the flow mod done (the removal of the choke system) What does this mean?

 

that means it has no choke. yes, stage 2 jetting means it comes with a jet kit. i would start off with around a 146 dynojet and see how it runs. you may need to lower the needle clip a position too.

 

sorry about that, i ment RAISE the needle clip a position. raising will make the jetting a bit leaner, which you will need considering he probably had this setup for a 400ex.

 

So does taking off the choke do anything?

 

Also my air tub should fit on the 400ex carb right?

 

Its tight but will go. I have done that swap. From a piped quad to a piped quad I didn't change any jetting. That was awsome luck, I normally don't have.

 

yes, it will be tight. all you need to do is take the air boot off and put it in a pot and boil it on the stove if you can't get it on. that should expand it enough so you can get it on.