my 400ex started to make a whistle noise when you give it gas. it sounds like it is coming from the top of the motor. maybe from the head. it runs fine. the idle and get up and go is all good. anyone know what this could be?

 

HEY!!!!!!! i found out what the whistle was. i had a leaking head gasket. yup it was blowing out right under my headers. now we know!

 

Glad we could help. LOL glad you found the problem! [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/beer.gif[/img]