150 4 stroke dies

I've got a friend that bought a 150 4 stroke with close to 1000 hrs on it. when he pulls back on the throttle to come off of plane, it dies when he puts it in neutral. Could it just be ideling too low, or could this be another problem? Is there an idle adjustment on the throttle linkage?

[boats.net]

Probably need to put on computer to test sensors and idle control valve.

I guess the idle control valve isn't adjustable?

[boats.net]

No it's not.