Yamaha 40 hp 2 STROKE throttle plate at wot.

[maineiac5586]

Working on a 1989 YAMAHA 40 HP 3 CYLINDER 2 STROKE precision blend manual start TILLER . I noticed when I put it in forward gear and twist the throttle all the way to wide open the throttle plates are only opening a 1/4 way. They are not going to full horizontal as I expected. Haven't used the motor yet just going over it all. I don't see anything that I can adjust. The throttle grip is going all the way to full but not sure if the plates should be like this or not. There is a screw on each carb with reverse threads but that Seems to only adjust how far they open when in neutral and just cracking the throttle. I played with these SCREWS but to no avail. I put them back where they were originally. The manual says to adjust the wide open throttle stop but I don't see how that can be what needs to be adjusted. The control LEVER is nowhere near that stop when it goes to full throttle. Help please