1992 Mercury 5hp outboard. What is this red port?

[Hypobaric]

Hi Friends, Does anyone know what this red port is on the underside of my 1992 Mercury 5hp,
Model 100521MK, Serial # 0A887746? See pictures. Thank you!

 

[racerone]

Flush plug I believe.

 

[Hypobaric]

Thank you. It's amazing that you can't find it in any of the parts drawings. So, there is a flush plug on the lower unit, and this one on the powerhead. Can one run the motor if the one on the power head is attached to a garden hose?

 

[racerone]

Seems to show it on the parts page I used.

 

[QBhoy]

I don’t think it’s a flush port at that age. I think your tell tale pipe there might not be original and your original one might be plugged up. Not sure. Certainly not a standard thing on that engine.

 

[Cieara_Vintage]

Thank you. It's amazing that you can't find it in any of the parts drawings. So, there is a flush plug on the lower unit, and this one on the powerhead. Can one run the motor if the one on the power head is attached to a garden hose?

Im having a hard time finding the drawing and schematics for this exact motor. My 1992 5HP Mercury MLH Serial# 0A883575 is nowhere to be found online unless I purchase a printed copy which I don't have time for. Any suggestions, or would you be willing to share?

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