Jim Rojas wrote:
Do you know if there is any way to add a weep hole so I can tell that my
lower unit impeller is working? My previous boat had a 150HP Mariner
outboard. The weephole is a great feature to prevent blowing the motor.
And of course the alarm would go off. I sometimes go to a large lake
that is full of some kind of fresh water kelp growth.

Thanks

Jim Rojas



There already is one, of sorts.

The exhaust manifold is raw water cooled, and exits the drive through
the exhaust relief ports in the gimbal housing. BUT, you can't see this
while under way, and it takes a trained ear to notice the difference at
speed if your impeller fails you. You should familiarize yourself with
the temperature gauge and how it indicates while everything is working.
This will be your best indicator. There may also be a temp warning
horn, I can't recall.

If you feel you cannot proceed w/o a telltale, you may be able to splice
into the line the feeds the exhaust manifold and attach a small diameter
tube to pee within sight of the helm. Where that would be on an I/O I
haven't a clue. I don't know if there is enough pressure at that point
either, or if it will sap enough volume off of the manifold to cause an
overheating issue.

Rob



The '86 era 165/170 Mercruiser is a closed cooling system(this is a
later version of the infamous 470).

Rob