jetting

[Fast350ex]

I recently bought a used 400ex with a curtis sparks 440 in it. It has trouble starting, and when it does start I have to keep the throttle going higher than the idle or it will shut off, It also sputters through the air filter and when it is running the air filter makes a sharp sucking noise I tried setting the idle ajustment but it doesn't work. Is it the jeting or fuel or what, I really would like help.

Thanks

[cals400ex]

are you running an aftermarket ignition box? i would change the plug for sure. also, what are all the mods on the bike? what jetting you running? make sure both air boots on the carb are tight and don't have any cracks in them. this can cause this problem