1973 20hp Johnson. No fuel pass the fuel pump

[ewalden444]

Hello All,

I have a problem with my 1973 20h.p. Johnson motor. First a little history about the motor.

I purchased the motor used last year, replaced the points, fuel pump, and kill switch, and got the motor running good. I used it twice. The first time ran great not problems. The second trip was for three days. The first day motor ran great, The second half of the day, the motor would not get past idle (No mater how far I turn the throttle). The three day I just run it in idle.

It would always start on the first or second pull. I brought it home and I was having trouble starting the motor.

Well I put it away until now. I started working on the motor, and it looks to me that the fuel pump has gone out. I get fuel from the tank to the pump, but not to the carb.

Is there a test I can run to verify that the pump has gone out?
Is there anything else I should b looking at?

Any help would be great!

Thanks

Ed

 

[JB]

Re: 1973 20hp Johnson. No fuel pass the fuel pump

Go to Engine FAQs, Ed.

In the "Outboard won't start" article there is a procedure for testing the fuel pump.

1

 

[F_R]

Re: 1973 20hp Johnson. No fuel pass the fuel pump

So, you get fuel to the pump. Do you get fuel THROUGH the pump--that is can you remove the outlet hose and get fuel when you squeeze the primer bulb?

If you get fuel at that point, but no further, then either your carburetor's float valve is stuck shut, OR it is already full. Have you removed the drain plug from the carburetor to verify whether or not there is gas in there? While you have the drain plug out, look at the end of it. Is it shiny bright or does it have a coating of varnish on the end? If varnished, you might as well accept the fact that the rest of it is varnished also and needs cleaning, especially the high speed orfice jet deep in the hole behind the drain plug.

Your description of your 3 days strongly indicates that it was running on one cylinder on day 2 and 3. That's ignition problems, not fuel.

BTW, a fuel pump, good or bad, won't keep it from starting.

 

[kenmyfam]

Re: 1973 20hp Johnson. No fuel pass the fuel pump

Carb blockage ?? ignition problem ??
Need to know if any fuel is making it to the cylinders. Are the plugs soaking wet after you try to start it ??