250x wiring PLEASE HELP

[lil_billy_300ex]

hello, my brother has a 1988 250x, he striped it down to the frame and put a bunch of aftermarket parts on it for racing, well anyways he put a different 250x wiring harness on it becuz his was all fooked up, he also thew on a pro design thether switch on it, we wired it up but it wont start. we have spark getting to the plug. but it seems like kills itself before it runs. can u please help us out, we are tring to get this thing running by this friday to race.

[nj300exr]

try takin the key ouyt of the kill switch t0 wear normally the motor would shut off, sometimes people hook them up backwards so really when the key is in the circut is broken but when its out the circut is complete