Spedo pitot on 89 80 Merc

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
Does any one know where the speedo pitot is on a 1989 80 horse Merc? I have looked everywhere on mine and I can't find one which leads me to believe that it doesn't have one. What kind of set up do I need to get my speedometer working?

Thanks for your replies.

Wade
 

jebeebe

Petty Officer 1st Class
Joined
Nov 26, 2006
Messages
322
Re: Spedo pitot on 89 80 Merc

There should be a tiny hole in the leading edge of the lower unit just above the gear houseing and a tube coming out just above the cavitation plate, if yours has one. My 89' 150hp had one................Jerry
 

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
Re: Spedo pitot on 89 80 Merc

Yes i did find it. It is there but the speedometer is not working. What do I do to determine if it is the speedo or the pitot?

Wade
 

Willyclay

Captain
Joined
Sep 8, 2006
Messages
3,264
Re: Spedo pitot on 89 80 Merc

The easiest one to check first is the speedometer that works on compressed air in the line caused by the water pressure from the pickup. Just shoot some LOW pressure compressed air into a line connected to the fitting on the back of the speedometer. Vary the pressure if possible to check the movement of the indicator. If that checks okay, then put your boat in the water with the water pickup line to the speedometer disconnected from the meter end. Put it somewhere you can monitor and see if water is being pushed through the tubing when the boat is underway. That should tell you where the problem is. Good luck.
 

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
Re: Spedo pitot on 89 80 Merc

Thanks very much I will give that a try. As a side note my boat has a small leak I can't find. Now I am wondering. if that might be the problem. A hole in the line? Hummm!
 
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