losing fuel pressure in the priming bulb

[djenkins]

hey guys i am new to the boat scene and im trying to do stuff myself to save a little money. i have a 1999 johnson 50 o/b on my 16ft mitch craft. about 10 minutes after i get the boat underway it steadily loses fuel in the bulb. but its runs fine if you keep priming it..the whole time. i have already tested the bulb and it checks out to be fine. hopefully some of yall can tell me what my problem might be. thank you in advance!

david

 

[oldcatamount]

Re: losing fuel pressure in the priming bulb

Disconnect the fuel line that goes from the fuel pump to the carb. Crank the motor a few times and see if fuel pump is working. If it works, you probably need to clean and re-build the carb. Also check all fuel lines for leaks and loose clamps.

 

[ezeke]

Re: losing fuel pressure in the priming bulb

The 1999 50HP motors were sold with either a OMS fuel pump or a conventional lift fuel pump - which do you have?

Diagrams here: http://evinrude.cust.shopatron.com/

 

[djenkins]

Re: losing fuel pressure in the priming bulb

Disconnect the fuel line that goes from the fuel pump to the carb. Crank the motor a few times and see if fuel pump is working. If it works, you probably need to clean and re-build the carb. Also check all fuel lines for leaks and loose clamps.

thanks you for the advice...i dont have the boat with me right now, its down at the coast guard station where i work. i will check back with yall tomorrow afternoon.

 

[djenkins]

Re: losing fuel pressure in the priming bulb

The 1999 50HP motors were sold with either a OMS fuel pump or a conventional lift fuel pump - which do you have?

Diagrams here: http://evinrude.cust.shopatron.com/

i not too sure..like i said in the pervious post im not sure which one i have because its stored at my work. ill check back tomorrow.

 

[djenkins]

Re: losing fuel pressure in the priming bulb

The 1999 50HP motors were sold with either a OMS fuel pump or a conventional lift fuel pump - which do you have?

Diagrams here: http://evinrude.cust.shopatron.com/

On the motor it has 50PLEEA I'll post a few pictures and hopefully yall can tell which one I have. Sorry I'm so illiterate when it comes to boats, it's my 1st one.

 

[Daviet]

Re: losing fuel pressure in the priming bulb

By the parts breakdown it looks like you have a OMS pump, there is a rebuild kit available for it.(man is it expensive)
Normanlly if you can cure the problem by squeezing the primer bulb when the problem happens it is a fuel pump problem.

 

[djenkins]

Re: losing fuel pressure in the priming bulb

By the parts breakdown it looks like you have a OMS pump, there is a rebuild kit available for it.(man is it expensive)
Normanlly if you can cure the problem by squeezing the primer bulb when the problem happens it is a fuel pump problem.

Thanks for the helpful advice. I'm off this weekend so I'll do alot more investigating. Do you have an idea of the cost of a new OMS fuel pump? If not that's ok, I will try and look it up tomorrow.

 

[ezeke]

Re: losing fuel pressure in the priming bulb

Thanks for the helpful advice. I'm off this weekend so I'll do alot more investigating. Do you have an idea of the cost of a new OMS fuel pump? If not that's ok, I will try and look it up tomorrow.

The list price of the OMS pump for your motor is $406.

The test procedure is outlined in your factory service manual. That's not an item that you usually replace unless you have had it tested.

BTW, you may have noticed that in the parts catalog for your motor there are two lines listing fuel pump, one for the OMS, the other for the conventional lift pump. Look at it a different way; do you have a separate oil tank?

 

[djenkins]

Re: losing fuel pressure in the priming bulb

No I do not have a seperate oil tank.

 

[ezeke]

Re: losing fuel pressure in the priming bulb

No I do not have a seperate oil tank.

Then you may have a conventional premix lift pump #438557. You can buy the current replacement pump for that or convert to one for around $100. from your BRP/Evinrude dealer.

There are also repair kits to rebuild that pump - part #0438616.