Old Johnson Sea Horse project **FINISHED**

[Drowned Rat]

Hi guys. I just picked up 2 old Johnsons. One is a '54 5.5hp and the other is a '57 18hp. They both have a two line fuel setup. I'm assuming one is a return line?? Is this correct? I have a tank with a 2 line hookup. Do these motors use fuel lines with priming bulbs? Do they have a fuel pump or does the tank need to be pressurized?

My second question is: on the 5.5hp there is a red wire coming out the bottom of the stator (I think it's called a stator) and a black grounded wire that are run together taped with electrical tape (obviously not original). These wires go nowhere, they are just cut. Could these have served to charge a battery or something? I have no idea what they are for.

Thanks so much for your time.

 

[JB]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Howdy Rat.

The second line is a pressurizing line. Crankcase pulses are used to pressurize the tank itself. There should be a pushbutton pump on the tank with which to prime the carb.

Without pulling the flywheel and looking I don't know what those wires are, but I suspect that they are the result of some past creative engineering exercise.

 

[Drowned Rat]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Thank you JB. The tank does have a small "Poppet" looking button that depresses and is spring loaded. It's quite small though. Does pushing this button repeatedly pressurize the tank?

Agreed about the mystery wires.

Thanks again.

 

[mikesea]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

there have been some posts instructing how to convert the old pressure systems to more modern fuel pump.Those tanks had explosion problems ,among other problems that led to breakdowns.I'm thinking the wires are possibly old kill button leads,do you see anyplace a button may have been,putting ground to the points was one was to kill it

 

[Scaaty]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Tanks are no problem. Lets get the motors running first!If the hoses are good and no leaks, nothing will "blow up". Laings sells ALL the parts for them. There should be no extra wires coming out of the ignition system, all under the flywheel. Leave them loose and see if ya got spark. Those old Johnny's just about always need new coils, so I would pull the Flywheel and check for cracks. New are 20 bucks..do it anyway. Simple motors, and should be no problem if ya have at least 60psi in the jugs. On checking the tank, go out side, take the hoses off the tank, put some gas in it, and pump the push knob. Shoots out gas, yer fine. New twin hose is 2 bucks a foot at Laings outboards

 

[Drowned Rat]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Perfect, thanks for the great info. These motors look to be in very good condition, just neglected for many years. I'll think they'll clean up fine and live again. I'll post the progess. Thanks!

 

[Drowned Rat]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Okay, one thing at a time. Scaaty, I followed your instructions for checking the tank. No gas comes out although when I plug the "gas" side with a finger and push the primer, it builds pressure quickly ( a couple of pushes) and becomes hard to push. No gas though. plugging the "air" side has no effect. I also sprayed the entire tank with soapy water to see if there are any leaks when pressurized and there do not appear to be. Could the lines inside be clogged with old gas? Rust or something? The mechanism appears to work, just no gas comes out. Also, I only put very little gas in the tank. Maybe it's too low? Needs more?

 

[Rick K]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

D.R., besides what everyone else said, be sure to check the O rings in the connector. Plug the connector into your motor, and pump 'er up 5-6 times, and listen for any leakage at the connector. O rings are cheap, but they can be a pain to change.

Also, there's 2 kinds of tanks - the old style has a metal button, and the new style has a black plastic button. Both will work, but the rebuild kits are different.

There's nothing wrong with these tanks, my dad got the motor I now have, back in '59, before I was even born. It's had one tank for all these years, and I continue to use it to this day. All I ever did was replace the lines and the O rings.

Call Jeff at Laings - 800-463-9001. He has everything for these motors/tanks you'll need to get 'em going. His shop is right down the road from me - he's a great guy, is very fair price-wise, and will do you right every time.

Email me at chevydriver37@yahoo.com, if you'd like a diagram of that tank, and all it's parts.

 

[Drowned Rat]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Thank you Rick. I did check out the Laings website. He and I will be doing much business in the coming months. The tank has only barbs, not a connector. The 5.5hp has a connector that looks similar to current Johnnyrude connectors, only with 3 prongs instead of 2. On the 18hp, the fuel lines go directly from the barbs on the tank to barbs on the carb and breather. Any correct size fuel line could be used. I'd like to pull the top off the tank and take a look inside, but that would guarantee I'd need to buy a rebuild kit for the gasket if for nothing else. BTW, I have the metal button style tank and it appears sturdy and well made. I think I'll try putting a little more gas in the tank and see if that works. I'll email you right now for the diagram, thanks!

 

[F_R]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Don't be misled. Pumping the primer button does NOT pressurize the tank. It only pumps fuel up the hose and into the carburetor so you can start the motor. The running motor pumps air back down the second hose to pressurize the tank and force more fuel out to the carburetor to keep it running.

 

[Drowned Rat]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Okay, thank FR. Nobody told me it pressurized the tank, I was just asking if that's how it worked so it's my lack of knowledge. Thanks for the info.

 

[steelespike]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

The one drawback to the system is the connector they are very expensive.They are however rugged and somewhat rebuildable.No doubt someone replaced the connector on the one motor.

 

[Rick K]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

F_R, Hmmmmmmmm. Now you got me thinking.... Do you think I might have a problem with my tank then? I pump it up about 5-6 times and start her up. After running around the river all day, I crack the gas cap at the dock, and it sits there letting pressure outta the tank for about 10-15 seconds.

Is this NOT the way it's supposed to be? Is any pressure that's built up in there during the running process somehow supposed to be vented some other way? I know there's a vent screw on top the tank, but that's always been tight.


Thanks
Rick

 

[F_R]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Drowned and Rick, I apologize if I came across wrong. It is just such a misconception that many have about how the thing works.

Rick, your tank is normal. The motor pumps air into the tank which pressurizes it. The air pressure stays in there untill you loosen the cap, then it escapes with that nostalgic hiss that all us old timers enjoy. BTW, the tank also has an overpressure relief valve that vents excessive pressure buildup from sitting out in the hot sun, so the thing about them blowing up is also an old wives tale. However, a busted hose will squirt gas all over the place, so make sure the hoses are in good shape and not rotten.

 

[Chinewalker]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

A few other points to make. You actually should crack the cap open after a day on the water to relieve the built up pressure. I leave mine slightly loose when not in use so as to not build up any pressure in the sun, etc. Built up pressure can cause problems in any tank - pressurized system or not. I just tighten the cap before using the motor again. The pressure systems are a time-proven system and with proper care will work just fine...

Both of your motors should have the same connection at the motor. Let me know if one is missing the male end at the motor, as I have a few of those connectors kicking around.

On another note, be sure you're running a 25:1 mix in both motors, one quart of good TCW3 rated oil per six gallons. Also, check your lower unit oil frequently - unless the seals have been redone recently, you're running on 50+/- year old seals... The shift rod seal is subjected to the most abuse and is often the source of water intrusion in the gearcase.

- Scott

 

[Drowned Rat]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Thanks CW. I'll be sure to follow those tips. I do need a connector for the 18hp. If I can get them running, I'll probably get new L/U seal kits for them. I just finished washing off at least 20 years of built up grime off the 5.5 and it looks amazing. Mint green and cream colored. I turns over nicely with compression although I haven't tested it yet. That's next.

 

[tashasdaddy]

Re: Old Johnson Sea Horse fuel question

Re: Old Johnson Sea Horse fuel question

Drowned Rat, if you are mounting the 18hp permanently on a boat. the only reason to get the fuel connector is to remove the tank from the boat to refuel. it will run for ever with the direct connection. seawaymarine.com has the connections, but be ready for sticker shock. you can ocasionally fined the connectors on ebay. i just sold a '55 15hp rude. dumbest move i ever made.

 

[Drowned Rat]

Re: Old Johnson Sea Horse fuel question *PHOTO*

Re: Old Johnson Sea Horse fuel question *PHOTO*

Tahasdad, I figured that was the case. The long hoses hanging out are just unsightly. I'll try ebay though. I'm going to concentrate first on the 5.5hp. It is 100% complete and easier to manage for my first refurb!

Here is how I found it at a garage sale. $10.00

Here it is after a little cleaning.

I put more gas in the tank and gas still won't come out when pushing the priming button. I did pressurize the "air" side and gas came spewing out though. Does this mean the primer is bad or am I still missing something. Here is what I want to try just to see if I can get this thing running. I want to put a primer bulb on the air side line so I can pressurize the tank with that. My question is, will the bulb being inline effect the pressure pulses coming from the crankcase. This is only a temporary measure to get the thing running.

I checked compression, 65 upper and about 62-63 lower. Is this good? This is after one good pull.

The upper cylinder has good spark, but I can't get a spark on the lower. A cracked coil I'm assuming from what you guys have told me so far.

Thanks!

 

[F_R]

Re: Old Johnson Sea Horse fuel question *PHOTO*

Re: Old Johnson Sea Horse fuel question *PHOTO*

Taking what you have said so far, that is the primer will build pressure against your finger at the fuel nipple, and gas will go through if you blow air into the tank, I come up with just one educated guess: The check valve disc #37 is missing or has crud under it. (Let me know if I guessed right)
Any way that you can rig up to put some pressure in the tank while the hose is connected to the motor should fill the carburetor and allow the motor to be started at least. Got compressed air? Connect the hose to the motor, blow some air into the air nipple on the tank and slap the hose on it before it all excapes back out.

 

[Chinewalker]

Re: Old Johnson Sea Horse fuel question *PHOTO*

Re: Old Johnson Sea Horse fuel question *PHOTO*

Hi DR,
If you don't get a good squirt of fuel out the "FUEL" side when pumping the primer, then something is plugged up. Might be time to get into the tank and the top canister assembly. I would not try to cobble a primer together as you may end up pumping some grime or goo into the motor. Take it apart, clean it and see what you've got. Rebuild kits are available - see them all the time on eBay, and as mentioned before through Laing's...
If you can't find one of the male ends, let me know - I've got a few of them kicking around...
- Scott