I bought an 04 400ex but the neutral light won't go off even when the keys off only if its in gear

 

ah i had this problem too check all the wires up front under the plastics make sure they are all connected correctly also check your neutral safety switch on the left side of your engine its just a wire that runs to the bottom of your case on the exterior you will see it

my problem was the neutral light didnt go off and i didnt need a key to start it then i did the wiring correctly re connected some things and i was good!

 

Your neutral light is running directly to hot. Trace it and run it to ground.