671TI throttle return spring

https://www.glendinningprods.com/wp-content/uploads/2018/01/tb06.pdf try this procedure. It fixed my throttles moving back.

Ka-Boomer ! The spring on the governor end where it hooks onto, came be moved around just a bit up or down. It doesn't move much, nor does it need to to get the pull just right. You can move it around with the spring still on , btw. You need to have tension on that booster spring. When you get it right you will see the difference. You should have a nice smooth stead range through the travel of the throttle.

It’s pretty easy job , but with boats as always nothing is easy.... and other priorities take precedence.
You can do it at the dock , I assume you know that.
Has to be with the motor running.

that’ll be great getting the bottom done you should pick up a lot of performance with the boat after having that done.
Mine needs to have the bottom done also.