i have an 87 250x and i was wondering if a 300ex carb will fit it with same jettings and everything

 

they are so close in cc size i would guess yes. mabe dial down the pilot jet if it seems rich

 

should work they are both 29mm. 250x main jet 125,pilot for an 87 250x is 35....91-92 is 38....300ex main is 122 with a 38 pilot. so i would say put in on and see how it runs, you might need to jet you might not.

 

i put the carb on today but didnt have to much time to mess around due to work but i start it and it dies. it wont stay on unless i keep giving it gas. when i start it i smell gas so its getting to much gas, should i jus turn the pilot needle up and see what happens or do u think i should get new jets for 250x.

 

to answer your question from your other thread you started just swapping the pilot screw does nothing, you need to swap out the pilot jet. while your in there might as well take out the 300ex 122 main jet and put the 250x's 125 in there.

 

how do u change the pilot jet?

 

better question on the pilot jet thing, where is it at, i can change it if i kno what to take apart

 

take the float bowl off you'll see the main jet its a hex jet that sticks out, the pilot is the one next to it but its down inside the carb body and has a slot for a screw driver. i take it you do not have a service manual so the next best thing is go to powersportspro.com and look at the parts fiche.

 

thanks and i have a manual, it doesnt go in great detail with the carb