Logo
FULL SITE MENU

1982 Johnson 50 HP Outboard, Fuel Pump?

D

dschex

New member
I have fixed/tested many things on this 1982 Johnson 50 HP outboard that I purchased in July 2017. New coils, powerpack (the old one was okay), rebuilt fuel pump, new plugs. Compression is good, 140 psi each cylinder.

It would not idle so I rebuilt the carburetors and it idles smoothly now. However, last fall it stopped running at full throttle, it would cut out after 10-20 seconds. This spring I squeezed the fuel bulb while at full throttle and that solved the problem. It seems like I have a fuel delivery issue.

Today, I put a fuel gauge on the output to the fuel pump with a tee-fitting while running the engine on the hose. The fuel pump output was only about 1.5 to 2 psi at a slow or fast idle. I read somewhere it was supposed to be 5 to 7 psi.

Should I purchase a new fuel pump? They are about $20 on eBay. Could it be something else? If I squeeze the primer bulb the pressure jumps up to 5 - 9 psi--then i stop squeezing. No leaks anywhere. I loosed the fuel tank cap to ensure no vacuum.

Could the pressure pulse be an issue? Anything I have overlooked? Is there a good fuel pump brand (other than OEM, as they are pretty pricey)?

Thanks for the help.


Dave.
 
Sorry for such a long delay in following up on this.

I did put a new fuel pump in (I purchased a Teleflex Marine 18-7352 Fuel Pump), it had even lower pressure but solved the problem...for a while. Then the same problem returned.

With fuel delivery issues, I have since learned a very simple trick is to put a clear line or filter before the pump. If you see air bubbles, somewhere you have an air leak. I did see air bubbles in mine.

After spending a bit of time trying to find the source of the leak, I just replaced the Attwood fuel hose and primer bulb (lots of online complaints about Attwood fuel hose) with a factory Evinrude fuel line and primer bulb. Once I did that, the boat ran for hours and never skipped a beat--no more air bubbles visible on the way to the fuel pump.

Along the way, I put some lucas power steering stop leak fluid on the pins of the fuel connector on the gas can (old style 6 gallon steel Cruise-a-Day gas tanks). In case those were leaking air (not sure), I wanted to swell those seals to be sure they were sealing correctly.

Please let me know if you have any questions.

Thanks.
 
I got a 1984 85 50 or evenrude clean the carburetors and run but then it acts like it's starting for gas I put an inline 3 to 6 psi fuel pump on it and it seemed to work better for a minute but then it went right back to doing the same thing so any suggestions on what I can do I've put new pools new power pack The stator's Good the triggers good new plugs it just acts like it's when you give it gas it runs for a minute and then box down like it's running out of fuel do I need to get a higher pressure fuel pump inline fuel pump
 
Back
Top