1959 HP Johnson Outboard - Questions

[dpostman21]

I have what I believe to be a 1959 18 HP Johnson Outboard (no tag on transom mount). I have a couple questions, any help is greatly appreciated.

Question 1 -
Motor starts up, idols smooth, revs up good, BUT... when running it at full throttle it seems to stay at full throttle even when throttle is moved backed to slow. Everything appears to move with the throttle both ways. It appears to stay wide open only when I rev up to full throttle, have to hit the kill switch to bring it back down in which case it idols again. From an idol If I just give it a little gas (or up to half throttle) it comes back down to idle no problem. Any Ideas???

Question 2 -
After I started the motor for the first time I notice no water was coming out of the exhaust, so I immediately shut it off. After looking it over I noticed the water was coming out of the bottom cylinder area into the lower cowl. I am thinking there is a freeze plug or something on the bottom (side of cylinder head facing towards water) of that cylinder. I stuck a piece of thick rubber underneath it and water came out of the exhaust perfectly. Is there a plug that is supposed to be there?

Here is a video where you can see the grey rubber I put underneath to push the water thru exhaust: [video]https://goo.gl/photos/CnxGTVzMGKBzu4MX8[/video]
Here is the video you can see the water pouring into the the lower cowl [video]https://goo.gl/photos/CnxGTVzMGKBzu4MX8[/video]

Photos:
https://goo.gl/photos/MAmefryQiDTvT9tm8

https://goo.gl/photos/h3PqERX8mcp53ZCm6

https://goo.gl/photos/WyNHiUWwVKRQR3v57

 

[flyingscott]

For the throttle check to make sure the carb is closing and the butterfly and or linkages aren't sticking. As far as the water it looks like the powerhead base gasket has failed that will need to be fixed.

 

[F_R]

Question #1--are you running it in that tank when that happens? Do you have it in gear? If you did, it would have emptied the tank, so I suspect you had it in neutral, which probably was causing what is called runaway.

What are the numbers on the disk on the side of the cylinder? The model number may be there. Serial number will be for sure.

#2--I can't make out where the leak is. Suffice to say, find it and fix it.

 

[oldboat1]

Water leak looks offhand like a lower head gasket leak. BTW, running with a low water level imo.

 

[dpostman21]

flyingscott - Thank for your input I will check to see if the the carb is closing and the butterfly and or linkages are sticking. Also will check the power-head gasket. Thanks!!!

F_R - Yes in a trash can when it happens have not had it on the boat yet. I did have it in neutral, never ran it up in gear, great point!!! Agreed on the leak, I will seek out the culprit. Thanks for your input!!

oldboat1 - I will certainly look into the lower head gasket. I will try to get a deeper barrel to run it in. I appreciate your insight!!