- This topic has 9 replies, 4 voices, and was last updated 1 month, 3 weeks ago by
.
-
This is a “non-bailer” Scott made motor.
I’ve been trying to get a new Sierra 18-3072 impeller to
work to replace the original, NLA.It’s the same OD at 1.890, and I believe I bored out the shaft hole
to .500, from .420.
The main issue with it was that it was about .040 too short, so
I removed the liner and machined it down to match the shorter
impeller.The cover sits atop the pump liner with an o-ring atop of it, and
the seal plate compresses the o-ring, and holds the cover down
tight against the impeller.
Being that I machined down the liner height, I had to shim up the
o-ring slightly so it would compress when bolted up.I put the motor all together this past winter, and when I got it
running this Spring, it would not pump water.
I’ve been trying to test it out with the gearcase in the test barrel,
spinning it with my cordless drill.
It will barely pump above the top of the gearcase.There is no obstructions, and the liner can’t get out of orientation.
It looks like it should pump but doesn’t.
What am I missing?VIDEO……..
https://youtu.be/x0SJQoG7SrgI machined down an aluminum puck to fit inside the liner
to get the liner machined down even so the liner cover is
touching the impeller.
I shimmed-up the o-ring to be sure
that it compresses and holds the pump
housing cover on tight.
Prepare to be boarded!
I think I made progress today getting the Sierra 18-3072 impeller swap pumping.
I shortened the impeller cartridge to match the impeller height, plug a hair
for a little “squash”. Also, I drilled a tiny hole in the housing just above the water pump,
near the suction side, in case the pump was getting air locked. It’s all back together now,
and hope to barrel test it tomorrow.Impeller in cartridge. Cartridge is now machined down so the impeller has
a little “squash” when the cover is down tight.VIDEO….
https://youtu.be/mdnEldlSG6g
Drilled a little “vent” hole here so pump can’t be air locked
when the motor is lowered into the water. Probably not
necccessary, but I was getting desperate!
Prepare to be boarded!
That does look promising! I just watched the video.
It’s been said here that that is the reason why impellers have the thin strip of rubber in the circle and onto the blades…..because when they are “squished”…..it will only be that small surface area that makes total contact…..thereby reducing friction.
It’s also been said here that it’s not the best idea to “shave” impellers down to make them shorter….because in doing so you remove those thin strips. Your chosen method did not require such modification!
Great job! Sure hope it works up to your expectations.
I was able to test run the Corsair in the barrel today …..
Animated Fire Hose Sound / ASMR / 46 Minutes
I prayed to the “Outboard Gods” that it pumped water this time.
My prayers were answered, but the camera, or operator,
malfunctioned. 🙁It pumped great, blowing water out of the little pee hole
in the bottom of the welch plug in the head, and
out of the holes in the exhaust.Motor is attached to the boat, so hopefully the first boat test
of the year soon, and hopefully the camera works!When I tried out the fuel line fitting from my Firestone tank
prior, it spewed gas while squeezing the primer bulb.
I took the fitting apart yesterday, chucking the large OD in the lathe
to hold it, then heated it up with the little propane torch, and
twisted the latch end back and forth until it pulled apart.
Cleaned it up, installed new a O-ring, and Loctite it back together.
Worked good today, no leaking.
Prepare to be boarded!
I was thinking you had to have a poor seal at the top and/or bottom, but your picture didn’t seem to show it. The impeller looks to be at least at the top, if not a bit above the cartage. Not having any experience with those, I felt it best not to comment. It probably wasn’t an air lock, but the problem with doing more than one thing at a time is you don’t know for sure which one was the solution. I have a lot of experience doing just that. Seems that after thinking it through, you figured it out anyway. I narrowed an impeller for a Mercury but didn’t use it. It exposed the brass center. I couldn’t see where running metal to metal (brass to the aluminum cartridge, or cover) was a good idea. I have a picture of it somewhere but cant find it.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.
I always found the Corsair models to be an interesting “looking” motor. How did they fit everything under the covers? If one had crossed my path there’s a good chance I’d own it. Its probably my good fortune that never happened.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.
“A LOT lighter” has become a priority for me lately.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.
- You must be logged in to reply to this topic.