RE: [omc-boats] Source/photo of speedometer pitot pickup

Hi Ethan,

Good to hear from you! The original pitot pickup are made of
unobtainium.

But here's a close-up photo of how I replaced mine with any of the
commonly available inexpensive modern pickups. This style pickup is
available most anywhere.
http://hhscott.com/evinrude/images/DCP_0132_small.JPG

I've since glassed over the old screws where the original pickup was
mounted (visable to the right). Here you can see where I used RTV to
seal them. While you're at it replace the vinyl hose, as the old hose
gets dried out and becomes very brittle.

BTW, the 40-year old speedometer with this pickup was amazingly accurate
when clocked against a handheld GPS (once up on plane).

Lee Shuster
Lib1@...
 
 
-----Original Message-----
From: owner-omc-boats@... [mailto:owner-omc-boats@...]
On Behalf Of Ethan Brodsky
Sent: Tuesday, May 02, 2006 3:37 PM
To: omc-boats@...
Subject: [omc-boats] Source/photo of speedometer pitot pickup

I recently discovered that the speedometer on my '70 Evinrude Explorer
(155
hp OMC V-6), which I had believed was broken beyond repair, is simply in
need of a new pitot tube. The system is mechanical and pressure-based -
there is a rubber tube that hooks up to the back of the speedometer,
runs
to the stern, goes through a thru-hull fitting in the transom and then
into
the water. The tube on my boat is broken off just outside the
thru-hole,
so I'm not sure what kind of pickup was used originally. Does anyone
know
of a source for these? Otherwise, I'd appreciate it if someone who has
a
similar system could take a few pictures of theirs, so I can try to
build
one myself. I'm guessing it's just a simple block with a hole in the
front, but I'd like to get the inlet size correct.

I've been having a pretty good year with the boat, so far. It's now on
its
second season after my outdrive rebuild two winters ago. The ball gears
still look good, the gear backlash still feels similar, and I haven't
noticed any oil leakage. I took the boat out of storage about a few
weeks
ago and we've been out a half-dozen times or so.

Of course I've still had some problems. The tilt system seized over the
winter and I burned out the tilt motor servicing it (and destroyed the
hammer-blow coupler during disassembly), but parts were fairly easy to
find, not too expensive, and it went back together fairly quickly. Had
I
fixed the problem before wrecking the motor, none of this would've been
necessary, but I think the motor was on its final legs anyway.

I also had some problems getting the boat started for the first time
this
year due to a seized check-valve in the fuel system - I just removed the
valve and it's been working fine. I don't think having a check-valve is
necessary with a electric fuel pump (with a mechanical fuel pump, it
would
improves starting by preventing the fuel lines from bleeding down during
non-use). However, I suspect the valve is also there to prevent fuel
from
siphoning out of the tank in case of a fuel line leak, so I'm planning
on
replacing it at some point.

As for my long-term projects, I've completed a few of them and others
are
still pending. I installed a drain valve (Fumoto F101N) to simplify oil
changes - next time I just need to run a hose from the drain valve
nipple
out the bilge drain hole and flip open the valve. Hopefully this will
prevent me from ever again needing to clean four quarts of oil out of my
bilge.

I also managed to remove the cover from the tilt clutch gearcase,
replace
the cracked bolts, and made a new gasket to seal it up. Water leaking
into
the tilt housing has been a recurring and extremely annoying problem as
long as I've had the boat, so I'm thrilled to have that fixed. The
clutches still appear to be in pretty good shape, so hopefully I've
fixed
it before anything is damaged personally.

No progress on improved instruments in my dashboard. I'm still looking
for
an OMC 172075 combo oil-pressure/water-temp gauge, but I haven't seen on
on
ebay in a while. Now that I have some hope of fixing the speedometer,
I've
been leaning more towards adding small additional gauges instead. I've
also been toying with switching over to electronic ignition, as I've
seen
some fairly good deals on ebay for Pertronix systems.

No wakeboarding yet (we're in Wisconsin), but we've been diving a lot
from
the boat and have recovered a nice anchor and a decent set of patio
furniture.

I found another decent vendor that stocks a lot of small OMC parts and
has
reasonable prices. They're "Seaway Marine" in Seattle, WA (800)
332-0803.
I was referred to them by go2marine (who also has an amazing OMC
selection,
though they have a $20 minimum order).

Hope everyone else is enjoying their boats,

Ethan

-- 
<A HREF="http://www.engr.wisc.edu/~brodskye/"> Ethan Brodsky </A>
UW FutureCar Team Paradigm: Two-Year FutureCar Challenge Winner
UW-Madison Clean Snowmobile Team: Winner of the 2004 SAE CSC
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