Originally Posted by Rogue Wave
It is my belief that taking the interlock out of a rib/outboard combination is dangerous and therefore shoudn't be done. So don't do it!
Saw a nasty incident partly due to a lack of an interlock on a Pacific 22 in Lymington a few years ago. Chap jumped out of the boat when it was alongside, flicked the bow rope from one side of the console to the other - caught the throttle lever - instant full speed ahead! Totalled three RIBS that were moored up. Ended up on top of the pontoon!
Back to the single / twin lever options:
Sounds like the single lever set up you have needs some adjustment. You should get a definite click into gear AND THEN NO MORE SLACK TO INCREASE REVS.
Should be the same whether outboard or inboard diesel.
If not then there is either a loose cable clamp inside the head unit, worn detent springs / ball etc or worn throttle cable ends.
Have used twin lever systems on inboard engines and they can be quite good on hydraulic boxes. Allows a slightly higher idle speed which can be nice for maneouvering. Have also used them on a twin sterndrive set-up. Awful.
Give it a go and let us know how you find it.