backfire in carb?

[bens250ex]

i recently bought a 400ex and installed a pipe and filter, i uped the main jet but now when it first starts up it want to backfire it seems in the carb. i also have to turn the choke on full to get it to stay running when it first starts up. what would be the problem? can someone tell me how i can fix this

[underpowered]

you are to lean on yoru pilot jet. bump it up a few sizes and adjust your air/fuel screw. try a 42 pilot and about 2 1/4 turns out on your air/fuel screw.

[hornetgod13]

Definitley going up 1 size (40K) on your pilot would be a wise call. A temporary fix might be to turn your fuel screw out a turn to turn and a half until you get the stock pilot jet swapped out.

[bens250ex]

ok im new to messin with a 400ex so could someone tell me were the pilot is , and were the fuel screw is.

[hornetgod13]

Use the search feature. There are a ton of threads already out there answering those questions.