The throttle lever on our boat, has about 1" + slack in the response. Is this by design ?? I assume that it is.
I agree there some times is a little bit of movement that you feel in the lever after you have shifted into gear and trying to advance the the engine speed, But if you think it is too much then you might be able to remove some of the slack by readjusting the throttle cable at the engine side, Because some times you could get extra slack at the shifter if some one did not adjust the cable eye end where it hooks up to the carb/throttle body just right, The eye ring could be off a few turns and you might feel it in some cases. Some times it takes a few tries to get it 100% right. And it could make you go .the slack is normal, the lever has to put the drive in gear before it applies the throtle.