I picked up a 5.5 hp 1961 johnson seahorse cd-18 about a month ago.
motor didn't run right so I (or my uncle and I) rebuilt the carb and replaced the fuel pump.
so I took it out today for the first time and it ran great at first, then I noticed the water was spitting fairly aggresively as opposed to running like a hose like before.
I called my uncle and he said to order a new water pump, but it should be ok to use sparingly as long as it's still pumping some water.


well, a few hours later on it started stalling after about a minute of running.
it would start fine and even rev up to full throtle, then it would slowly just die
it started making a hollow scraping noise under the hood as it started to die out when I finally called it quits and limped back on my trolling motor.
I ran it across some shallow sand at one point before this happened but I killed it quickly so I don't think this had anything to do with it, but I figured it was worth mention. (the water pump was iffy before this happened, I didn't clog it.)

I plan on ordering the manual, but what could this be?
did I kill it?

also, do these not have a actual independent water pump? I just see kits... is the housing built into the lower unit or something?

Hopefully you didn't overheat and burn that little guy up.

Take the lower unit apart and see if you need the entire kit, it is probably a good idea just to replace it, while you have it open, instead of just replacing the impeller. Might be smart to go ahead an replace the lines too.

The impeller was probably dry rotted and crumbled up a bit when you ran it.

I owned a 63 iirc, rebuilt the carb several times before I gave up on it and bout a new Merc on clearance.


Iirc the pump on those is about the biggest pita to get to on those. You gotta remove the motor and pull the shaft and it's accessible from the top down. You're lookin at several sets of gaskets as well.
Good luck.

I'm voting overheated and screwed.

Your uncle should never have told you that it was OK to use an impeller older than 3 to 5 years old (used or not) if anyone cared about the motor.

Yes, plenty of people have gone somewhat longer on somewhat older, but it's just not something non-rednecks do.

Huh? Four bolts and the shift linkage. Drop off lower unit. Pump housing is right there on the top of the lower unit. Easy peasy.

Trouble is, it's probably almost seized now. OP, look at the engine block and see if the paint is discolored or burnt looking. The exhaust cover on the block will be the first to show signs of severe overheat.

Do a compression check before wasting money on water pump parts.

compression should be fine, it starts really easy and runs good for a bit before it does anything... off, or just dies
I doubt I overheated it because I really only ran it a few minutes the last time before I gave up, and it was still spitting water out decently. the water coming out was warm, not boiling.

the hollow scraping noise sounded almost like what I'd imagine the flywheel to sound like it it was scraping on something.
I was in a hurry to kill the engine instead of investigating closer

In that case, I'd be looking at the ignition coils under the flywheel. They are prone to cracking and intermittent spark. The points and condensers may be shot also.

As far as an overheat, it doesn't take long for an outboard to get real hot especially at high RPM's. Like 15 seconds without water and it's toast.

I think I know what did it...
I couldn't find good info on the right oil mixture before so I took the previous owner at his word and used 50:1
turns out they didn't start reccomending 50:1 till 63.

would there be any harm in adding more oil, draining the fuel line, emptying the filter bowl and trying to start it repriming with the new mixture?

It won't hurt a thing, however, I would recommend a compression test before dumping any money or frustration into it. Turning it over by hand isn't a good enough compression test. It has to be at or near 100 PSI for it to run properly.

Less than 100 PSI and it may run, but won't run right and you'll be chasing your tail trying to find out what's wrong with it.

I don't remember off the top of my head, but this model (running 25:1 ratio) may have a type of "plain bearing" crank. If the crank journal is scored (from low lube) it can't seal the cylinders from one another and again, you'll be chasing your tail. This won't show up on a compression test.

Sometimes the compression will show good, but scoring in the cylinders will screw you. You may not see the scoring unless you remove the exhaust cover and inspect the cyls thouroughly.

I hate to be harping on the compression, but I've seen too many engines people waste time and money throwing parts at that won't ever run right because of compression or crankcase leaks.

What ever happened to this motor???


CMOS

I'm curious myself. Lets see if this works..

@netofficer3710  

What happened with the outboard? Inquiring minds want to know.

it's still sitting in my uncles garage
he hasn't gotten around to working on it yet, but when my hours pick up I may take it to someone that just opened locally to see if he can figure it out.

in the meantime I have a 61 5 hp sea king I picked up from a guy on ebay

Glutton for punishment or do you just like old outboards? I love old outboards. I've got my grandpa's 1958 Johnson 3hp Seahorse I semi-restored a few years ago and another 1958 Johnson 18hp I need to restore.

I still haven't started up the 3hp since I "restored" it. And the kicker...I don't even own a boat to put either of them on!