1999 Johnson 4 hp. How is this supposed to work?

dockrat100

Petty Officer 2nd Class
Joined
Mar 22, 2011
Messages
144
https://www.flickr.com/photos/dockrat100/11278298755/
https://www.flickr.com/photos/dockrat100/11278422623/
https://www.flickr.com/photos/dockrat100/11278300405/
https://www.flickr.com/photos/dockrat100/11278367144/

I recently acquired a 1999 Johnson 4 hp, J4REEA. The previous owner apparently cobbled together a get around fix on some of the fuel lines, as well as buggered up the throttle cable. The throttle cable looks pretty self explanatory, but how are the other lines supposed to work?

The rusted off nipple is supposed to be a pulse line, apparently going to the carb, but why is it necessary?

How does fuel get from the external tank to the fuel pump? The way these lines are run it seem to not go through the fuel pump at all?

I am used to much older motors, help!
 

dockrat100

Petty Officer 2nd Class
Joined
Mar 22, 2011
Messages
144
Re: 1999 Johnson 4 hp. How is this supposed to work?

Even if someone can post pictures of what it is supposed to look like, that would help.
 

orbanp

Petty Officer 1st Class
Joined
Jun 26, 2011
Messages
324
Re: 1999 Johnson 4 hp. How is this supposed to work?

Looks like that motor had two versions of the fuel pump, one mounted on the block, what you have, or the other, mounted under the carb float chamber. The blocked off lines are the pulse lines for the pump under the carb.
Looks like they switched over from one version of the fuel pump to the other at some time.
The line that curves away backward on your picture from the top cover of the fuel pump should go to a fuel line connector mounted on the engine.
The other line from the pump goes to the carb float chamber.

These pictures should help:
Johnson Cylinder & Crankcase Parts for 1999 4hp J4REEA Outboard Motor
Johnson Fuel Pump Parts for 1999 4hp J4REEA Outboard Motor
Johnson Carburetor Parts for 1999 4hp J4REEA Outboard Motor

EDIT: Correction, that engine might not have had different fuel pumps, but it looks like that blocked off pulse line was used on motors with integral fuel tanks. So they might have switched over from integral tank to remote tank.

Peter
 
Last edited:

dockrat100

Petty Officer 2nd Class
Joined
Mar 22, 2011
Messages
144
Re: 1999 Johnson 4 hp. How is this supposed to work?

It has a valve on the choke knob to select if you want fuel to come from the internal tank or an external tank. It would make sense to me to have the internal tank gravity feed into the carb, and run the fuel line from the external tank to the fuel pump, and from there into the carb, but it appears to not be that way now.
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,719
Re: 1999 Johnson 4 hp. How is this supposed to work?

the motor should have an integral tank with the facility to connect a remote tank. hence the two pumps and the valve operated by the choke knob

If you are using a remote tank you need the square fuel pump shown in the second of orbanp's links. It gets its vacuum pulses directly from the crankcase via the mounting. It feeds to the nipple #33 on the carb diagram via hose #4.
Hose #12 connects the fuel line connector #1 ( for the remote tank) to the filter cap #8 on the pump

If you have an integral tank it is controlled by the tap operated by turning the the choke knob. It feeds to the nipple next to the housing for the bladder #32.

The bladder together with the two check valves #31 forms a pump for fuel from the integral tank. It is operated by vacuum pulses from the rusted off nipple #22 via the pulse hose #21 on the crankcase diagram, connected to the nipple #9.

I imagine that if you do not have both tanks unused nipples should be blanked off

Gosh I hope you can follow that!


blue refers to the pump diagram
green refers to the carb diagram
red refers to the crankcase digram
 
Last edited:
Top