73 Johnson 115 - Run away engine Questions

[Yotadude83]

Hi,
So I’m pretty new to boating just bought my first boat two weeks ago and have been working on getting the engine running smooth.
Sooooo yesterday I was doing some work on it and i was told it has been a few years since it’s been ran regularly. I got her running but she was stuttering a little when given more throttle. I figured hey before pull the carbs I would run some seafoam though the engine and see what happens. Well after about 11 mins I noticed the idle seemed kinda erratic so I shut it down. I waited about 5 mins and said well maybe it’s supposed to be like that…. Soon as cranked her again she went from idle to full throttle, tried to turn the key to power off..nothing, ended up having to pull the fuel line and waited for it to run out which was around about 20-30 seconds. All in all it ran full throttle for about two mins or less. I guess my question is where do I go from here and what do I look for… I’m guessing the water pump is toast. I was able to turn it over after it happened but today I get nothing. Guess I should look for melted wires as this thing was hot!

Any suggestions? Thanks!

 

[brodmann]

Were you running it with no water going to it? When you say you ran some seafoam through the engine, how exactly did you do that. Did you add some seafoam to a gallon of gas? Did that gas have oil mixed with it, or do you have oil injection? Did you have an overheat horn go off while it was racing? See if you can turn it by hand. If not, you're screwed. If you can, you're lucky. Since you said the water pump must be fried, then I have to assume you had no water going to the motor. I don't understand why anyone would do that.

 

[Yotadude83]

Were you running it with no water going to it? When you say you ran some seafoam through the engine, how exactly did you do that. Did you add some seafoam to a gallon of gas? Did that gas have oil mixed with it, or do you have oil injection? Did you have an overheat horn go off while it was racing? See if you can turn it by hand. If not, you're screwed. If you can, you're lucky. Since you said the water pump must be fried, then I have to assume you had no water going to the motor. I don't understand why anyone would do that.

Were you running it with no water going to it? When you say you ran some seafoam through the engine, how exactly did you do that. Did you add some seafoam to a gallon of gas? Did that gas have oil mixed with it, or do you have oil injection? Did you have an overheat horn go off while it was racing? See if you can turn it by hand. If not, you're screwed. If you can, you're lucky. Since you said the water pump must be fried, then I have to assume you had no water going to the motor. I don't understand why anyone would do that.

One gallon of mixed gas/oil with a can of seafoam, and nope she was running in a stock tank full of water. I’m guessing the water pump is fried because the midsection was super hot but that could be because of the exhaust too maybe. I will try and rotate it by hand and update. Oh sorry also I didn’t hear an overheat alarm go off.

Update: I ran out and checked, the engine will turn by hand so it’s not seized.

 

[Crosbyman]

better find the kill circuit....and fix it