question for the outboard experts
 

I have a 1998 Force 40hp on my Cougar Cub. it is missing the trim tab which I have ordered but on the diagram there is a "water tube" and "screen" shown. the tube goes in at an angle with a plug on the housing. what is this tube for? it is #40 on this diagram
https://www.mercruiserparts.com/bam/...00283/28185498
the screen is #42. I dont have the plug or the screen at the moment but will be ordering what ever is needed just confused what it does as it goes up under the trim tab so I dont see how it supplies any water. any one know?

I think that should be the water pickup tube for cooling the engine. I'm confused by the diagram too, but I'm guessing the screen goes on from underneath, and the tube goes in from the top of the lower?

Edit: Nope, I'm probably wrong, the main water tube is https://www.mercruiserparts.com/8m0042794-tube-water-lg

Found a video... Looks like that is a water intake screen, and then the tube faces forward from there. You can see it after he removes the trim tab. Guessing the water intakes in the usual position are not adequate for cooling, and maybe this is additional cooling water supply?

that is it. still dont know the purpose as some have it and some dont. seems that up and running it would not get very clean water with the prop spinning there but what do I know.