95 mercury 150 revving up to full rpm on start up

[DavidGalini]

What would make a outboard rev to full rpm in neutral, I have checked the throttle linkage and everything is moving freely, all the butterflys are seating where they should be and yet the motor goes full blast on start up in neutral? Please help.

 

[jimmbo]

How far are you advancing the warmup lever? Which 150 is it? Carb, EFI?