2004 Yamaha 40hp Erratic Idle In Neutral

[JuiceSD]

I have a 2004 Yamaha 40hp 2-stroke which I purchased a couple months ago. The motor runs great when it is in gear, however multiple times throughout the day the idle will increase to as high as 5000rpm when the motor is shifted to neutral. It will stay there for a while and drop back down to a normal idle. This does not happen every time it is shifted into neutral. Does anyone have any idea what my problem might be. Thank you.

[99yam40]

You need to see what the throttle linkage is doing when this happens