Posted by blacksmithdog on 05/11/11 - 12:42 PM
#1
I have a 2011 Mercury 25hp motor on my 13' Whaler. I know that some newer outboards have built in pitot tubes on the front of the lower unit. Do they all these days have that? How can I tell if mine does?
Thanks!
Posted by Finnegan on 05/11/11 - 1:21 PM
#2
Mercury introduced that feature in the mid-range and larger outboards in 1978 I believe.
If your engine has it, there will be a small hole in the leading edge of the gearcase, and there will be a closed off barb on a small section of tubing for the hose connection at the lower engine support. It's very easy to determine if yours has it.
I should also mention that this system is more efficient (creates more air pressure in the tubing) than a pitot fitting attached to the transom, and because of that, requires a Mercury branded speedometer for an accurate speed reading. A generic speedometer will read too faster than the boat is actually going.
Edited by Finnegan on 05/11/11 - 1:24 PM
Posted by Binkie on 05/12/11 - 7:00 AM
#3
Your 2011 Merc. 25hp 4 stroke is probably the same as my 2008 model. Mine is actually built in Japan by Tohatsu, and is the same motor as the 25 Tohatsu with a different style better looking cowling. There is no speedometer pickup on this motor. You can easily tell as there is a small hole in the leading edge of the gearcase, where a rubber tube would fit that goes to the speedo. I have a Faria speedo mounted on my 13 footer with a pitot tube mounted on the transom. It reads the same speed, 29mph at wide open as my GPS.
Posted by Binkie on 05/12/11 - 7:07 AM
#4
Larry, I had a pair of 1984 Merc 115 towers (BOUGHT NEW) that had the speedo pickup built into the leading edge of the gearcase. Can`t say they were introduced in that year though, It also was the first year of the prop rated hp . The 115 prop rated put out the same power as the earlier crankcase rated 150`s.