1956 Johnson 15 hp fuel issues

[aMeyers11]

Hi everyone. So I ended up getting a 56' Johnson 15hp with the boat I purchased last summer. Never really got around to It. But put some tranny fluid down the cylinders. Pulled her over. And it feels and sounds like it's got plenty of compression. Also tested spark and to my surprise it has spark. I knew I needed a pressure tank for this motor and i decided to do the fuel pump conversion instead. This involved removing the carb and the whole plate that the carb attaches to. After removing it I was instructed to take some weird piece out and plug a hole with a vaccume cap. I re assembled and made a new gasket. I ordered a briggs style fuel pump off Amazon called "HIPA" installed it went to test the motor tonight and primed it and ball got hard, but I noticed no fuel in the sediment bowl at all. So I took the hoses off the opposite 2 ends(vaccume and carb) of the fuel pump and no gas in either? I rechecked the diagram and it seems right? Do you think just Chinese garbage pump or what? After coming to this realization I just connected the carb straight to the tank and primed it. Sediment bowl filled up but the hose wasnt tight enough so I'm not sure if it filled the carb enough to get to the cylinders as it didnt fire at all. Does anyone know if the motor would be able to sputter off being primed with the vaccume port open? I'm most concerned about this stupid fuel pump not working as it is very important to making this whole thing work. Anwyays sorry for the long winded question if anyone has any advice I would gladly appreciate it. I'll drop pics below.

 

[Crosbyman]

those pumps are getting darn cheap ..price wise now

first thing first do a blow test on the pump air should flow in to out but not out to in connect fuel lines accordingly

in to out you may have those reversed which is why fuel did not reach the bowl

vacum goes on the top nipple

no reason fuel can't reach the fuel bowl unless something plugged or the pump fails the blow test

get fuel to flow ….chase the other problems after one at a time

make certain your engine mod is ok I plugged (sealed) one of the channels as in the video and removed the little check valves and did not use a rubber plug .

https://www.youtube.com/watch?v=FtG4M7ye1N8

the easiest way would have been to get a cover plate with pump mounts and install a pump directly on the cover
or drill a side cover and mount a pulse nipple and simply plug the air pulse nipple behind the carb wit ha piece of hose

 

[aMeyers11]

Thank you for the response that helps a ton! I believe I need to diagnose if the fuel pump is any good via the blow test and then work from there. I'm sure I got the lines mixed up, although i did follow the diagram instructions i think. Bought it cheap on Amazon though so who knows. And yeah I followed the instructions in that video except I didn't do the scotch filled stuff but instead did the vaccume plug. In retrospect I proabably shouldve done the other methods but I'm sure it is okay for the time being. Once I get the fuel pump figured out I will try to prime the carb and see if fuel gets all the way into the cylinders and work from there. Than you for the help! I will drop some pics below.

it is currently very jimmy rigged, and I was just trying to see I'd it would fire. I got the motor added with my boat last year out of nowhere and I was pleasantly surprised to see that not only it isnt seized but it has spark in both cylinders and to me seems like it has pretty strong compression. Just hope I didnt screw with the fuel system too much.

 

[racerone]

Check your hoses.------Put way more water in your test bucket.-----The water pump must be submerged !

 

[Crosbyman]

if you have not pulled the flywheel you may have cracked coils which must be replaced unless you know they have been. Points should be inspected refreshed or changed plug wires may need to be replaced while you replace the cracked coils…

and you can time the engine
http://www.youtube.com/watch?v=ga1Cjymj6ms&feature=youtu.be

http://www.leeroysramblings.com/johnson_magneto.htm

a shot of gas in the carb should produce some… smoke and sputter make certain the throttle is past START in case the ring band is not lined up properly

you should relay check compression ...change the impeller …. you know … all the regular stuff.

all you need to know ...in the bible.. you can print needed pages to a PDF file or paper

http://www.boatinfo.no/lib/johnson/manuals/1922-1964johnson.html

save some money for fuel....they love gas :target:

 

[aMeyers11]

Thank you for all of the help I really appreciate it!

I'm going to compression test it just to be certain I'm not wasting time or money. If it has compression I'm going to diagnose the fuel pump issue and see if I can get it flowing correctly. I also plan to put a shot of gas through the carb and see if it sputters. This may sound stupid but when you say that do you mean pouring some through the top air intake or just priming it through the bottom? I should also add that the top peice of the air intake box is missing.

And yes I do plan to take the flywheel off snd inspect the ignition as I have no idea how maintained this motor was. The plug wires look original I think

as far as the lower unit goes. I drained the oil and found there to be a lot of water in it. So that's not good but I put fresh in and I'm waiting to get it atleast sputtering before I take the lower unit off to change the impeller and inspect the seals.

I just have one final question regarding the throttle. Last year(summer) the throttle handle turned fairly easy. I stored it in the garage over winter, but I noticed the throttle handle is very difficult to turn. I'm not sure what is causing the problem nothing is hitting the moving parts that advance the throttle? I'm not quite sure

anyways thank you for all of your help I really appreciate it!

 

[racerone]

There is a " friction piece " inside the throttle grip.-------Believe it or not you might try and remove / look at it and put some grease on it.-----Careful as the screw is a fine thread in aluminum and aluminum is easily damaged.----- You might remove plate and look through the inspection hole on top of the flywheel.---Allows you to look at the coils and points.

 

[aMeyers11]

And yeah my test bucket set up was pretty bad. Nerd to di it differently next time. I know the hoses are good, they are brand new. And I hooked the tank hose straight to the carb and gas started to go into the sediment bowl. So I know it was an issue of fuel going through the fuel pump. I must have the connections wrong. Or the pump is just cheap garbage. We shall see. Thanks for the tips

 

[aMeyers11]

Thanks for explaining the throttle grip. That will help. And I didnt know there was an inspection hole, I will have to check it out through there before deciding to remove the fkywheel.

 

[racerone]

Post pictures of the 2 coils please.

 

[aMeyers11]

I will when I get the chance to work on it nex! Hopefully tommorrow morning! We shall see

 

[Crosbyman]

https://www.ebay.com/itm/2-IGNITION...882968?hash=item3b11833918:g:jjsAAOSwwwRbKAz2

 

[aMeyers11]

Thanks for the link. Here's a video from the flywheel hole lmk what you guys think!
https://youtu.be/qjFaF9MwShk

 

[aMeyers11]

I think I figured out the fuel pump situation. When you say to give a shot of gas through the carb do you mean through the air box? Still trying to figuire out the stiff throttle and waiting to borrow a compression gauge. Thanks for the help everyone!

 

[racerone]

Ignition has been updated with new coils by previous owner.

 

[aMeyers11]

Alright everyone. I've run into another issue. I now have the fuel pump in the correct orientation. It works great at getting fuel to the carb. Problem is, the carb is leaking! So I can never get the primer bulb to fully stiffen. So It didnt run and i pulled the plugs and they didnt smell like gas. So I need to figuire out why the carb is leaking. Onto the GOOD news. I poured a little 2 stroke gas down the carb and she fired right up! She definetly has plenty of life left, just a matter of fixing this leaky carb! I will drop pics of where its leaking. Any help would be greatly appreciated. Thanks!

 

[aMeyers11]

Here is where It seems to be leaking

 

[kbait]

That’s the carb’s vent to atmosphere.. and needs to be clear. Yours obviously is clear as gas comes out. You have a leaking float valve (needle and seat aren’t stopping fuel flow when float rises and closes valve).. causing carb to overflow.

 

[aMeyers11]

I'm sorry I'm not really super experienced with carbs. Is that just an easy fix or full carb rebuild and clean?

 

[F_R]

A couple of common stiff throttle items:
1.The slow/start/fast dial plate acting like a self-energizing brake inside the twist grip. A few drops of oil will fix it.
2.The shaft between the twist grip and gear at the tilt is tight in the nylon bushing from corrosion around the O.D. of the bushing. Only cure is take it apart and clean & lubricate.
3. The bevel gear at the vertical throttle shaft where it sticks down into the nylon bushing is tight. Same cure as above.
4. And of course the friction plug.