Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Running Speedo tubing in a 1986 Montauk

Posted by Psiena on 05/14/12 - 7:23 PM
#1

I have a 1986 Montauk and am putting in a new speedometer. Old one is broken, tubing non-existent. I looked for a pitot pickup on the LU of the 1986 70HP Johnson that is on it. Nothing to be found there (I surmise it has none). So I am off to do a stern mount pickup tube. My question is the run from the sump well to the stern. What is the neatest looking path for it-- any ideas. Obviously the more hidden the better- would like to see any ideas of members and pics if you have any handy. Thanks.

Edited by Joe Kriz on 01/26/21 - 1:14 PM

Posted by Bake on 05/14/12 - 8:44 PM
#2

I too would think the 70 jhonson would have a tube. I would look around a bit before attaching a tube to the back of the boat.

the other thing is have you considerd using a gps for speed and putting something eles in the hole in the dash. You know those speedos are just an estimate of speed.

Posted by contender250 on 05/15/12 - 4:28 AM
#3

I have an 1985 evinrude 140, there is a small hole in the front of the lower skeg, then there is a connection right above the front of the lower unit, mine looks like a black plastic 90 facing upwards...Do not know if the 70 has the same thing...Personally I would not use a speedo, they never work correctly and with todays gps you can determine your speed

Posted by Psiena on 05/15/12 - 2:52 PM
#4

Well the speedo is to fill a hole-- the broken one is ugly, has to go. I have a fishfinder/GPS. So the new one is really there for looks and perhaps even redundancy for when the FF goes out.

Posted by Finnegan on 05/15/12 - 3:36 PM
#5

If you have to install the pitot pickup on the transom, you are best to run the tubing bundled with the transducer wires, up along side the engine bracket, over the transom and into the steering/ignition/control cable bundle up to the console. If done correctly it will hardly show.

It might look something like I have done here:

http://smg.photobucket.com/albums/v42...ic0025.jpg

Posted by Psiena on 05/15/12 - 4:29 PM
#6

Thanks Fin, that is just advice I was looking for!

Posted by Joe Kriz on 05/15/12 - 4:46 PM
#7

I owned a 1985 Evinrude 70..... No pitot tube on that model and Johnson was the same....

Posted by Tom W Clark on 05/15/12 - 7:03 PM
#8

I don't think the OMC 70s ever had the pitot in the gearcase. OMC pioneered this idea with their V-4 and V6 motors in 1982. After 1985 they had discovered that it was a great idea that did not work because gearcase pitot would clog the first time you hit any tiny debris on the water. 1986 saw the feature gone.

Other manufacturers, like Mercury, copied the idea and continue to offer it. Both of my Mercury 150s have gearcase pitots. They are worthless in Puget Sound because they will clog the first time you run the boat so I just pitched the speedometer after I bought the boat.

However, if you really do want a pitot speedometer, then mount the pitot tube on the transom (it has a spring loaded kick-up feature to protect it) and run the tubing just as Larry describes. That is how I always did it back in the olden days before GPS.

If anybody wants a transom mount pitot tube and some tubing, I have one in my shop I was thinking about pitching. I have an old speedometer too if anybody want that.


Posted by rarousse on 01/26/21 - 6:36 AM
#9

Hi Tom, do you still have that old speedometer? Think it would work in a 1987 13' BW Super Sport?

Edited by rarousse on 01/26/21 - 6:37 AM

Posted by Finnegan on 01/27/21 - 11:33 AM
#10

This is a 10 year old discussion, but for those interested in the speedometer installation subject, Faria now offers a drop-in speedometer gauge that has self-contained GPS functioning. No pick-up tubing required. They are about $150 but seem well worth the price considering the ease of installation, plus the perfect accuracy.

https://fariabeede.com/2-pages/prod_d...2_speedGPS

Posted by rarousse on 01/27/21 - 12:14 PM
#11

Thanks, I'll take a look and check it out. Appreciate it!