I'd say you're correct. it looks like someone botched the previous install.
Some of y'all may know I'm working on an F100 Yamaha engine that supposably locked up after overheating on it's previous owner. And that was a couple months after that previous owner had the engine rebuilt.
Anyway, I've replaced crankshaft bearings, and have had a difficult time getting it running. While doing so, I've run it briefly, and I've compression checked it, all while out of water. I didn't think it harmed the impellor, but I was wrong. I opened up the water pump and found this:
I took it apart, and was ready to install some new pump parts. And then I came across this (ignore the metal cup thing which I mangled removing it from the housing):
In the first pic, there is no gasket between the steel plate, and the impeller & it's housing.
In that second pic, that green gasket was found below the steel plate. I think that's wrong, that specific gasket belongs above the steel plate, and the housing.
The correct gasket for below the steel plate is pictured below (I already put it in it's place), and not the one I'm holding in my hand. When the one I'm holding in my hand is placed under the steel plate, I believe there's a gap then, which allows the impellor to suck air between it's chambers. Which makes for real poor pumping water action!!! Tell me I'm wrong?
Could this have added to this engine over heating on the previous owner.
Plus, when I did first start the motor after I put it together (when it was running poorly), I did run it in water, and I don't remember it peeing water out the pee hose. hmmm
Told you about peeing!
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You definitely found the problem. If the same guy who rebuilt the engine installed that water pump it kinda lines up with the rest of the story right. I'm very dyslexic so I lay the service manuals right next to where I'm assembling something or in a Outboard engine's case I use a computer outputting to a 24in monitor with Boats.net exploded diagrams pulled up. I match the part numbers before placing any part in place. No Guessing At All. The cost to replace a Powerhead to the possible monies made is too high a risk for me to even work anymore. Newer Boat owners do not have the common courtesies to know repairs do not happen fast, are not cheap, and are not warrantied against stupidity. Especially if they want perfection. My older customers knew, Rojo is not fast, he is not cheap, and he will close his shop if he thinks the Crappie are biting. They would pick up their boats and never return because I didn't fix something right. Today's Outboard Mechanics are parts changers not troublshooters.
I highlighted my favorite part.
And this is why I never trust anyone to fix my stuff. Except maybe Rojo.
I will try to fix it, learn from it, buy new parts, clean old ones, still don't work, start at step one. 100% of the time I come out ahead. Either by saving money, or by learning something I dint know, both ways, I'm a winner.
I’m buying Amazon stock immediately!
“If your too busy to fish, you’re too busy!” Buddy Ebsen
PROUD MEMBER OF TEAM GEEZER
(Billbob and “G” approved!)
Proud member of Tekeum’s Jigs Pro
Staff
https://heavenornot.net/
heavenornot.netSlab, Barnacle Bill LIKED above post
Wow. Ugly impeller. Glad it’s coming along nicely. Going to be fun
I was watching a Youtube video in which some youngsters had taken their dads big center console boat out. Boat was fairly new with a 250 Mercury hanging off the back. They loaded the boat on trailer, trimmed the motor up and pulled it half way up the ramp. The problem was the outboard was still idling out the water while they goof around. After about 3 minutes the motor blew a big puff of smoke and that was it . The guy shooting the video was in near tears because he knew that outboard cost 25k+. I found myself yelling at the video "turn off the freaking motor". I can only imagine how dad must have felt when the returned it.
S10CHEVY LIKED above post
Something along these lines might have happened with the previous owner ....
S10CHEVY LIKED above post
I believe you’ve found a good part of the origin of the problem. What I want to bring up is where do you think the missing parts went? My guru mechanic in TN told me of this in a motor. He worked on. A lot of the time they can be lodged in different placer within the powerhead causing hot spots from low or no water passage. That’s the worst one I’ve seen from someone I know. My Mariner went 8+ years before I changed it and it wasn’t pretty and started losing chunks. Check seals while you’re in the neighborhood. Shifter shaft and power shaft.
Creativity is just intelligence fooling aroundS10CHEVY LIKED above post