1985 90hp mercury inline 6 lower unit question

[B-Dozer]

Just bought a1985 mercury 90hp. got a great deal on it. spent about an hour getting it started because it had sat for about 2 years. got her to idle and rev just fine but it wasnt pumping water no problem just change the impeller. well when i took the lower unit off i found a 1/4 inch plastic line that I had never seen on a outboard. this is the largest outboard I have owned and I'm just not as familiar with mercury as i am with smaller omc motors. can anyone tell me what this is ?

 

[Blown Challenger]

Re: 1985 90hp mercury inline 6 lower unit question

Can you snap a pic of it?

 

[B-Dozer]

Re: 1985 90hp mercury inline 6 lower unit question

Yea i will take a pic tomorrow its a little late tonight .

 

[jimmbo]

Re: 1985 90hp mercury inline 6 lower unit question

Most likely the speedometer water tube. Those engine had a built pitot tube. if you look about a couple of inches above the nose on the leading edge of the gearcase you should see a small hole.

 

[carholme]

Re: 1985 90hp mercury inline 6 lower unit question

http://www.crowleymarine.com/mercury-outboard/parts/278_22.cfm

See item 2, which is the speedo tube.

Gerry

 

[B-Dozer]

Re: 1985 90hp mercury inline 6 lower unit question

Thanks Carholme thats it.

 

[bigtrout1949]

Re: 1985 90hp mercury inline 6 lower unit question

I'm no mechanic, but I would guess it is the speedometer connection. It has a hole in the leading edge of the lower unit. Hose can be extended to a speedometer in the dash. Hope this helps P.S. If the speedo is not being used the tube can be stored out of sight. Most just stick out a few inches. it should have a plug in it. Good luck