not runnin right!

[woodsracer144]

ok i got a 400ex with a yzf400 motor in it with a high port and polish and all that but the exhaust is messin things up.... i put a quiet core... i made it but i put it in and befor i tore it all apart i had it running and it was FAST! but then i took it apart, threw a LT rear shock in it and replaced the oil tank in it and then it runs like crap...
i dont know what it is... when you have it under load and you try to pin it it just bubbles like its starvin for fuel but you can have the clutch in and rev it all you want... i dont get it...


i pulled the plug that i put in for the quiet core out and then i ran fine for about amin. then it died... i didnt blow it up... i still have compression... but it wont start...

any know have any ideas.... the exhaust with out the quiet core that i mad it is is way louder than a pullin tractor or a bullin truck dragster... its just way too loud... people 7 miles away could hear me in the middle of a feild... i dont get it....
thanks

i might take a exhaust if anyone has one really super cheap.. thanks

[ss440ex]

Sounds like you plugged it up and its now running rich.

Try putting the other exhaust back on.

[woodsracer144]

put it back the ay it was and it ran fine for about a min... it would go like crazy then it just stopped... i havent looked in to since then...