Can anyone tell me what this is?

I have a '76 Evinrude 40 hp outboard, and I cannot figure out what this little plate is with the 5 holes in it. I don't want to take it off just to see what it is.

I am thinking of putting a hydrofoil on, and want to make sure that it isn't something that cannot be covered up. I'm guessing it's just some sort of access plate and those holes are to allow the water to drain out of the cavity when it is tilted, but that's just my uneducated guess.

Thanks in advance.

I'm not positive that I looked at the correct parts breakdown but based on what I found, that is a "water bypass cover". Doesn't sound like something you should be covering up or obstructing. Where is the water pump intake located on that motor. That was my first thought as to what it might be when I looked at the picture.

I'm with Mike - - - bypass cover

Looking on Leroy's Ramblings, this bypass cover was used to allow water to reach the pump when the motor was in reverse. When in reverse, the prop is pulling a slight vacuum on your water pump intake screen, starving the pump for water.

Similar to what he mentions on this page about 3/4 of the way down. ('74 6hp with same intake design)
https://www.leeroysramblings.com/OMC_6hp.htm

If possible, i'd find a way to clear some area on they hydrofoils around these holes. Won't need to be much.

Good luck!

kofkorn said:

Looking on Leroy's Ramblings, this bypass cover was used to allow water to reach the pump when the motor was in reverse. When in reverse, the prop is pulling a slight vacuum on your water pump intake screen, starving the pump for water.

Click to expand...

Bingo ... for when in reverse!

pretty sure a hydro foil wont hurt ya , when in reverse that section will be under water and you'll be just fine

Thank you guys!

Makes perfect sense. Tinboats rocks.