1978 115 hp Johnson outboard

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Hello fellow boaters, 1st time posting. I have looked at some great information on this forum and am excited to finally be a part of it. I have an issue that I hope someone can help me with. Last week while puttering around a local lake my prop quit turning. We did not hit anything, all of the sudden we just stopped moving. An inspection of the lower unit showed no visible damage. I removed motor cover and checked to make sure all linkage was working as designed and that looked fine. When the motor is in neutral and you turn the prop it sounds like there is something broken in behind the prop. Any Ideas?? This is something I am going to have to fix on my own as finances are tight. Any help would be greatly appreciated!
 

madolive3

Petty Officer 2nd Class
Joined
Sep 2, 2011
Messages
120
Re: 1978 115 hp Johnson outboard

I just bought the same motor last week and I'll be watching your thread, please come back and let us know what it turns out to be. I can't help you though, like Sergant Schultz I know nothing.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1978 115 hp Johnson outboard

Drop the mtr in fwd or rev, put some pressure on the prop and see what happens.
 

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Re: 1978 115 hp Johnson outboard

Thanks for the ideas guys, Blazinmonkey I found that part as well and am hoping that is what it is. Now the dumb question....how do I get to this pin? On my old motor the prop would come off as soon as the bolt was taken off. I took the bolt off on this unit and the prop does not come off. It looks like I need a wheel puller. Also does anyone know if coming in from the prop is the right way to get to the pin that monkey mentioned or do I need to drop lower unit and come in from the top?
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: 1978 115 hp Johnson outboard

Prop should slide off easily. Try banging on it with a mallet a little bit all the way around.
 

dazk14

Ensign
Joined
Jul 22, 2008
Messages
966
Re: 1978 115 hp Johnson outboard

Prop should slide off easily. Try banging on it with a mallet a little bit all the way around.

+1: rubber mallet if available, wood block between hammer/sledge and prop - hitting from bow to stern near the hub.
 

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Re: 1978 115 hp Johnson outboard

Thanks, how about getting to the pin is this the right way to go at it?
 

Joe Reeves

Supreme Mariner
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Feb 24, 2002
Messages
13,262
Re: 1978 115 hp Johnson outboard

Very unlikely that the shifter dog pin is at fault. In all my years of being in this line of work, I have never seen that pin fail. Troubleshoot as follows............

Engine not running, engine in neutral, turn the propeller by hand to get the feeling of resistance that is applied by the internal components.

Now, have someone put the engine in forward gear and continue to turn the propeller. If you feel a ever so slight increase in resistance, the problem usually is that the driveshaft sheared just below the water pump.

If so, and to check to see if this is indeed the problem, remove the lower unit and then remove the water pump assembly.

This may not be your problem but it is a common one. Of course, the driveshaft may be fine and the problem is actually in the gearcase... but you need to remove the gearcase anyway and a broken driveshaft would be the first thing you would discover.
 

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Re: 1978 115 hp Johnson outboard

Thanks Joe, not what I wanted to hear but good information anyway. I can tell you that when the prop is turned and the engine is in neutral there is no feeling of resistance at all. I can feel a click when I turn the prop and it sounds like two pieces of steel hitting each other in the lower unit. I will see what happens when I put into gear. Thanks again.
 

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Re: 1978 115 hp Johnson outboard

ok guys so the story gets better, I write this with a sick feeling in my stomach. So I raised the tilt on the motor to get a better angle to remove the prop (which did come off) I went to the garage to get another tool and came back to a pool of oil / water below the lower unit. After some more investigation I found that the lower unit skag had hit something and split. My buddy was using the boat the day before I got there and said he tapped a rock with it. Anyway I lowered the unit back down and drained the lower unit which was full of metal shavings, water and only a little oil. So now knowing that what am I going to find?
 

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Re: 1978 115 hp Johnson outboard

Joe, when the unit is in neutral there is no resistance at all. In gear the prop will turn about 1/4 turn and then stop.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: 1978 115 hp Johnson outboard

Due to the immediate and previous above post, it's obvious you have bigger problems. Tapped a rock? Tell your buddy to get his wallet handy.
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: 1978 115 hp Johnson outboard

You need a complete new or used lower unit.
 

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Re: 1978 115 hp Johnson outboard

Ok, so I just got finished getting sick......thinking aloud here, could a guy clean up the crack and weld, replace internal damaged parts and keep going for less than a new or used lower unit? Joe what would you guess went out in the lower unit? Where is best place to get new lower unit?
 

2008taurus

Cadet
Joined
Sep 23, 2011
Messages
10
Re: 1978 115 hp Johnson outboard

Guys, I really appreicate all the information that has been shared.
ok, so I was trying to drop the lower unit to at least get some oil on the parts that I can hopefully salvage. I took out every bolt that I can see that would be holding the lower unit up. but it still won't come off. What am I missing?
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: 1978 115 hp Johnson outboard

You need to disconnect the shift rod that goes the whole way up through the motor and connects to the shifting stuff under the carbs. You shouldn't have to remove the carbs to get to it (it is a royal pain though).
 
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