1956 15 HP Johnson SeaHorse Model FD 10 Long

[Minnow00]

Recently I picked this engine up and have had it out several times. It seems to run like new except for the duel line pressure fuel system. Motor needs to be pumped at the tank when fuel gets low to maintain pressure so I presume I have a leak.
Since it's time to either rebuild the original system or to convert it to a fuel pump and single line system I am wondering if there are any thoughts pro or con.
From what I have read, the reason pressure systems are no longer used is for safety reasons.
It seems to me if I have to spend about the same amount of money and work I would rather convert now to the single line fuel pump system.

I've searched the forum and was supprise not to find any info on this.

It seems that fuel pumps came into play on these motors sometime in the early 60's and initially they were attached to the sideplate just above the shift arm. My sideplate would need some remodeling if it were to be adapted.

If anyone knows how I can find the part number of a sideplate that takes a fuel pump mount I woud be grateful.

http://www.sschapterpsa.com/ramblings/Converting_dual_fuel_line.htm

 

[jbjennings]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

That's a nice motor you have!
If you need a fuel pump plate, you should pm F-R on this forum. He will take care of you.
Pressure tanks work fine, and have a pressure relief valve if it were to ever build up any high pressure. There are loads of people still using them just as I am and I've never heard of a real incident where the tank hurt someone. I'm sure there are, but I also bet that is true of modern tanks. Gasoline is dangerous! They only work off of 7-10psi of pressure, which is MUCH lower than your regular plastic tanks of today build up when you forget to keep the tank vent open.
However, I've converted a couple of my motors to fuel pumps and find it very handy for many reasons.
You can find a rebuild kit for your tank if it's not rusted out at laingsoutboards for about 25 bucks, and they sell 2-line hose as well.
JBJ

 

[Minnow00]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

Thanks jb, She powers a 12' modified jon boat with ease.
I just replaced the duel fuel line to the tank because I often fish alone and needed to put the weight of the tank in the front of the boat which required me to buy a longer line.
My decision is based on cost it appears I could sell the pressure tank on ebay and recover some of the costs to convert.
There appears to be another option to retrofitting with the special sideplate which employs a $20 Mikuni pump that would attach by hose to the existing pressure port on the manifold without any change to the sideplate. This conversion requires removing the carb and plugging one of the valves:
http://outboard-boat-motor-repair.com/johnson/Pressureized Fuel Tanks.htm
I believe my leak is in the quick connect at the engine and I can't believe how expensive those connections are north of 100 bucks, plus the cost of the tank rebuild kit.

Whose F-R? Can't find him in the member search...

 

[jbjennings]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

Dang Minnow,
If you don't know F-R, you don't know diddley!
He just answered some posts above, get on one and click on his name.

I have converted one with the manifold method you described, and it works, but in my opinion, the bypass cover plate method looks cleaner, easier to work with---heck, it's how OMC did it! If I ever do another, it's definitely how I'd do it. HOWEVER, if it's just a leaky connector, there's no way I wouldn't buy $2.00 worth of o-rings from laingsoutboards.com or vintageoutboards.com and fix the connector.
Once again, JMO,
JBJ

 

[Minnow00]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

Ok, and thanks again, I sent the message to F_R.
I also checked the tank and fittings with soap and after pumping it up there appeared to be no leaks. I think I may have exceeded the max length of line when I put the 13 ft on.
So now I am wondering if a fuel pump may have a little more umph and draw the fuel thru the 13 ft line????

 

[rjezuit]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

If the O rings in thr connector are bad/shredded or swollen or someone put in the wrong size they will cover the fuel port and it will not run. (personal experience). I would suggest buying a few O rings from laingsoutboards.com and trying them. If not the bypass cover conversion is easy and cheap. Rick

 

[Minnow00]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

You're right Rick, thanks. I'll get a new set of rings and put them in. Can't hurt for a few cents and could save me a lot of work too.

 

[jbjennings]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

Minnow,
There's several things you can do to check that tank. Let your motor run in the tank by pressing the primer for about 2 minutes and then unscrew the gas cap and see if pressure is building up. If no pressure, then you have a hole in the tank or bad gaskets. You should be able to locate the hole with soap and water or the gasket leak. If it's making pressure, it's bound to be a bad o-ring in the connector, or a bad sintered filter in the glass bowl or some other constriction of the fuel system. You can always take the filter out and run it and see if that's the problem. THere's quite of few things it could be, if the tank is making pressure.
JBJ

 

[Minnow00]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

I just got back in from checking the whole fuel line and everything seems good. Tank is taking pressure, soap shows no leaks. I'm wondering if I had some dirt or crap from the tank that got into the carb??? I recently got the engine and can't say how it was taken care of or winterized. I don't have a tub to put it in and run it at home and the launch is only 10 minutes away so Wednesday if weather permits I'm taking her back out and giving her another run before I commit to a pump conversion. Heck, it might just run like a top. But you say that I could clean the glass bowl under the carb? What just unscrew it and blow it out?? Looks like there may be a bit of sediment in there from what I can see.

 

[jbjennings]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

If your tank is building up pressure and putting fuel into the carb, which you should be able to tell if it is, then the tank and pressure system is not your problem. If it runs with you pushing the primer button but not otherwise, I would think maybe a float or needle/seat problem. You can clean that carb with no problem. It would be worth it to take the carb apart and look to see what kind of condition the float is in.
Since it is new to you, you'd be wise to get in the "top secret files" thread at the top of this johnson/evinrude forum and look at Joe Reeves' carb adjustment thread, and the points/coils thread as well. It could be as easy as setting the fuel/air mixture right on the high and low speed needles.
Good luck,
JBJ

 

[jbjennings]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

If your tank is building up pressure and putting fuel into the carb, which you should be able to tell if it is, then the tank and pressure system is not your problem. If it runs with you pushing the primer button but not otherwise, I would think maybe a float or needle/seat problem. You can clean that carb with no problem. It would be worth it to take the carb apart and look to see what kind of condition the float is in.
Since it is new to you, you'd be wise to get in the "top secret files" thread at the top of this johnson/evinrude forum and look at Joe Reeves' carb adjustment thread, and the points/coils thread as well. It could be as easy as setting the fuel/air mixture right on the high and low speed needles.
Good luck,
JBJ

 

[samo_ott]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

I dunno. Going back to the original post. If the tank button has to be pumped at any point to maintain pressure and keep the engine running then in my opinion there's not enough pumping air getting to the tank or there's a leak somewhere in the pressure side. If it leaked on the fuel side you'd see the fuel. Minnow, if I can offer a cheap option, I'd get a bucket or half barrel so that I could test it at home in a good test environment. It's sometimes hard on the water to diagnose.

 

[Minnow00]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

I think I will find something to test it in. I had the boat out a half dozen times and it was only the last time out that I had the problem. Maybe pumping the tank bosted the pressure enought to dislodge anything that may have plugged the supply or air. I dunno either. But I'm dying to find out and I'll find something to run her in before I go out and I can do a quick clean on the carb too. It didn't help that when I had the problem I was approaching the launch and the wind was blowing 35 MPH. I tried starting several times and it started but quit before I could get it into gear. I choked it and it ran a bit longer but soon stopped before I got far. I got it tied up to a nearby dock and put the tank between my legs and pumped it which got her runing fine and I can't be sure I needed to keep pumping but I can tell you that with the waves almost comming in the boat and there by myself I was not to focused on the motor.
Little excitement dosent bother me, I've owned big boats and had the same thing from time to time, just another part of the show....but I have never owned a motor with one of these pressure systems.
Thanks again for your help guys...

 

[lindy46]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

Try unscrewing the gas cap after the motor has run for a few minutes - does it release air? If not, the tank is not building pressure. If it does go "phttffff" then the tank is fine and you have a carb issue. Then I would remove the carb, clean it, and install a carb kit and new float.

 

[Minnow00]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

I put her down in a tub of water tonight and it starts up just fine but doesn't want to keep running unless I pump the tank. While pumping the tank manually I tried to throttle up and down and adjust the lean rich valves on the carb face plate and the motor ran rough and didn't seem to want to run good at higher speeds, it idled pretty good as long as I pumped the tank. I guess I will see if I can get a carb kit from local dealer, kinda wanted to go fishing Wednesday, looks like I might be playing mechanic.

Got any ideas on how I can be sure the water pump/impeller is working good? This motor is new to me and I don't know how much maintainence it has had over the years. It looks clean and paint is original.

 

[jbjennings]

Re: 1956 15 HP Johnson SeaHorse Model FD 10 Long

I just got back in from checking the whole fuel line and everything seems good. Tank is taking pressure, soap shows no leaks.

Minnow, I am still unsure. Is the tank pressuring up? Will it hiss really well when you run it a little while and ease the gas cap off? If so, you have a fuel restriction somewhere.

Actually, if that motor is new to you, you'd be better off pulling the flywheel and checking the ignition. There's a thread for that in the "top secret files".
Check the spark with a spark tester. Obviously at least one is giving good spark or it probably wouldn't run.
Then when you get a spark on both wires that will jump a 1/4 inch gap, clean your carb.
You'll have to remove the oval cover in the midsection to get to the shift shaft disconnect and remove the bolts in the lower unit to get it off and check your water pump. It needs checking since the motor is new to you.
That's about all the advice I can give.
good luck,
JBJ

 

[Minnow00]

1956 15 HP Johnson SeaHorse Model FD 10 Long

I fiddled with the motor and decided to hook the tank up on a short line directly to the motor. Got her started and sure enought the tank started hissing loudly. She was building pressure but it was leaking out from the cork gasket on the tank. Apparently the long line masked the leak. I ordered a rebuild kit today for the tank.
Hopefully case closed.