1958 Johnson Sea Horse..Name this part

dwreves

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Hi. I'm new here and have been working on a 1958 Johnson Sea Horse 35 hp (RDE-19C). I'm getting ready to take the carb apart to clean it since the engine starts but won't continue running, like it's starving for fuel. Anyway, there's a part on the motor that I just don't know what it is and wonder if I need to do anything with it at this point. I figure starting with the carb is a good place to start. I cleaned out the fuel filter and the plugs are pretty dry after she starts up. Take a look at the picture please and clue me in on what the part is and its function.

Thanks.

DaleSlide1.jpg
 

Joe Reeves

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Re: 1958 Johnson Sea Horse..Name this part

That's a vacuum cutout switch. It's purpose is to drop the ignition from one cylinder if it should be at a high rpm and NOT in gear, then suddenly have the throttle dropped. If this cutout didn't exist, it would be possible to have the engine run away to a high rpm where it would actually explode.
 

dwreves

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Re: 1958 Johnson Sea Horse..Name this part

Thanks for the response, I appreciate it. By the way, you have an extra E in your name...lol.

Dale
 

64osby

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Re: 1958 Johnson Sea Horse..Name this part

Before you tear into the carb make sure the tank holds pressure, the line is free of cracks, the connection is air tight and the motor is pressurizing the tank.

If all is okay, then it's time to rebuild the carb.
 

dwreves

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Re: 1958 Johnson Sea Horse..Name this part

The tank seems to be holding pressure pretty good and the hoses are in good condition, considering how old it is. There are a few air bubbles leaking out sporadically around the little primer button (not sure what the real name is) but the tank holds quite a bit of pressure until I release it by loosening the tank cap.
I did the carb rebuild and cleaning yesterday with some help from a very experienced, professional motorcycle mechanic. Installed brand new float and made sure it was level. Also, installed a new nozzle because the old one was stuck and gunked up pretty bad. We were able to get the engine to start and actually run for a while (2 times about 5-10 mins each) but it never really settled down into a smooth idle. To get it started we had to push the throttle up about 3/4 and had the slow speed valve open about 1 3/4 and the high speed valve open about 3/4. We pulled the plugs and they weren't as wet as we would expect, I guess. Just seems to me like it's not consistently getting enough fuel.

Is there any chance the vacuum cutout switch could be the source of the problem, like if it's malfunctioning? We just want to rule it out.

At least the water pump seems to be working just fine.

Dale
 

kfa4303

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Re: 1958 Johnson Sea Horse..Name this part

Hi dw. Glad you got her running (sorta). It's not likely that the vacuum cut out is the issue. It's designed to kick in under a "runaway" motor scenario. If it seems like it's not getting enough fuel that may be the issued. You can try squeezing the primer bulb while it's running. If it the rpms pick up when you do so, that usually means you have a fuel delivery issue. It only takes a small air leak to throw off the mix. Glad the water pump is working well. That is muy importante. Everything else can be worked out with a bit of fiddling and trial and error.
 

64osby

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Re: 1958 Johnson Sea Horse..Name this part

kfa, it's a 2 line pressure system, shouldn't have a primer bulb.

The leak on the tank could be part of the problem. Are the o rings in the connector still good?

You might try lifting the tank above the motor, gravity feed. See if the motor settles down.
 

dwreves

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Re: 1958 Johnson Sea Horse..Name this part

Ok, I had some time this morning again to try out elevating the tank. The motor keeps firing but won't actually run. The o-rings in the connector look ok to me, and the pressure seems pretty good...just a few small bubbles coming out around the little primer button on the tank but that's after I mashed on the button a few times.
I'll have to re-address the high and low speed settings I think. I pulled the plugs and they are pretty wet with gas, more on one than the other. The reason I mention the needle settings is because the knobs are not on the spindles, one of them had been stripped out and the other I didn't bother putting back on until after I get it running good. Now, if someone says to back it out 1 1/2 turns, I am assuming that means after screwing it in all the way clockwise, then backing it out counter-clockwise. My gut feeling now is I have the needle settings all jacked up and I need to start over.
I know I read somewhere else on this board about good settings for starting; I should probably start from there again.
 

Joe Reeves

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Re: 1958 Johnson Sea Horse..Name this part

(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle valve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 

dwreves

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Re: 1958 Johnson Sea Horse..Name this part

So I guess I need to do those adjustments once I get out on the water. I just went outside and the motor started up after just a few cranks and was idling pretty good. I let if run for about 10 mins then shut it down. It restarted again and ran for another 5 mins. It would idle pretty good at throttle position just above start, then would start to sound like it was getting thirsty again so I'd bump up the throttle a bit more to keep it running. It stalled out then wouldn't start again and I suspect I've flooded it. I'll let it set for a bit then go back and try it again. At what point do I take it to the water to actually try it out in gear, etc? I'm kind of nervous about taking it out with the intermittent starting I've got going on right now.
I also lowered the fuel tank back in normal position and didn't seem to affect the performance.
My fuel mix is 50:1, is that correct for this old engine? 50:1 was the recommendation from the local boat shop.
Another question I have is about all the gunk in the water barrel after I run this thing. After running for about 10-15 mins, the water in the barrel is what I would describe as very polluted with fuel/oil and it's very brown. I stick my arm down in the barrel afterward and looks like I work for BP. Is that normal for the water to get so gunked up so quickly?

Dale
 
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64osby

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Re: 1958 Johnson Sea Horse..Name this part

Pretty sure it should be a 24:1 mix.

Sounds like you still have an issue. Carb float needle, partially plugged passages, filter in the glass bowl is plugged, or air leaks.

Nasty water is normal and good. That is un-burnt fuel / oil that lubricates the motor.

Get it running good in a barrel before you water test. Rowing / paddling sucks.
 

nwcove

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Re: 1958 Johnson Sea Horse..Name this part

those initial needle settings are just that...initial....just to get the motor to start. they all react differently to needle adjustment.
if all is well with the carb, ignition, and fuel delivery, you should be able to get it to idle quite well in a barrel. dont pay much attention to the slow/shift/fast markings on the tiller....get used to listening to the motor. jmo
 

RogersJetboat454

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Re: 1958 Johnson Sea Horse..Name this part

My fuel mix is 50:1, is that correct for this old engine? 50:1 was the recommendation from the local boat shop.

Nope.
That boat shop has their mind on modern motors.
Yours should be running at least 24:1 if you want to keep it around.
 

dwreves

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Re: 1958 Johnson Sea Horse..Name this part

Thanks for the response. We were pretty thorough in cleaning out the passages but I wouldn't be surprised if they got gunked up again. When we cleaned them out there was quite a bit of flake type material that came out, I was pretty amazed at how much material actually came out.
The glass bowl filter was the first thing we checked and cleaned out but didn't do it again after the carb cleaning. I will definitely check it again.
We installed a new carb float needle as part of the rebuild; I will check it to make sure it's installed properly.
Something we didn't do as part of the cleaning was the hoses. Should I have removed the hoses and blown air through them or something?

Thanks guys for your help. I'm trying to remain optimistic about this motor.

Dale
 

HighTrim

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Re: 1958 Johnson Sea Horse..Name this part

Throw the old fuel line in the garbage. It is not ethanol proof, and is likely cracked it multiple locations. Coils and fuel lines are 2 items you can bet the farm on needing to change when restoring a 50s vintage omc.
 

dwreves

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Re: 1958 Johnson Sea Horse..Name this part

I just went out and checked the fuel glass bowl and it's full of crud already; I just cleaned it out a week ago. Also, I checked the fuel lines from the tank and they seem to be modern, like the previous owner had already updated them from the originals. But when I looked at the connection (see image) it looks like one side doesn't close all the way; should both sides shut off like the one on the left side?

DaleIMG_0516.jpgIMG_0517.jpg
 

HighTrim

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Re: 1958 Johnson Sea Horse..Name this part

Check your tank, ensure it is spotless inside. Change the orings in the connector. Add an inline fuel filter to the fuel line before it goes into the carb.
 

dwreves

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Re: 1958 Johnson Sea Horse..Name this part

Ok I went back and checked the tank by draining it into a glass bowl; quite a bit of flake-like crud settled in the bottom. Also, one side of the connector (fuel side) is stuck halfway open so I cleaned it out and is still half open; I guess could be a bad o-ring. Like I said before, there are some small air bubbles escaping around the primer button and now I see some around the gasket under the plate on top of the tank.
What do you guys think I should do? Is this tank salvagable...maybe replacing the gasket and re-sealing it? Or should I try cleaning it again? Or should I go ahead and swap out for a fuel pump?

I wasn't really looking at getting into a restoration of this motor, just put a couple hundred $$ into it to get it running.


Thanks and I appreciate it,

Dale
 

HighTrim

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Re: 1958 Johnson Sea Horse..Name this part

Cannot say if it is usable without personal inspection. If you are not sure of how to rebuild one, post a wanted ad at aomci.org for a known good pressure tank.
 
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