115 hp VRO fuel pump issue?

[bigredfish]

I have a late 90's 115 evinrude with the VRO pump. I mix my own oil and have disconnected several years ago. This past weekend the motor does not want to idle very long (about a minute). It actually is running out of fuel at idle. If i pump the primer bulb every 30 seconds or so, all is well. The fuel filters are clean, the tank vent is clear and with the motor off the fuel system will pump up tight with no leaks. I suspect the fuel pump is not pumping effectively at low engine speeds. At all other speeds the engine runs fine and bulb is tight. It only is soft and easy to pump when at idle.
please confirm my diagnosis.
Thanks

 

[countvlad]

Re: 115 hp VRO fuel pump issue?

I have a late 90's 115 evinrude with the VRO pump. I mix my own oil and have disconnected several years ago. This past weekend the motor does not want to idle very long (about a minute). It actually is running out of fuel at idle. If i pump the primer bulb every 30 seconds or so, all is well. The fuel filters are clean, the tank vent is clear and with the motor off the fuel system will pump up tight with no leaks. I suspect the fuel pump is not pumping effectively at low engine speeds. At all other speeds the engine runs fine and bulb is tight. It only is soft and easy to pump when at idle.
please confirm my diagnosis.
Thanks

when was last time the carbs were rebuild??? if not this year then i would rebuild the carbs and go from there... could be anything...

 

[SparkieBoat]

Re: 115 hp VRO fuel pump issue?

if it is you fuel pump and you are already premixing you can rebuild it...
http://www.maxrules.com/fixomcvro.html
How does the motor run out on the water?? if it runs fine then you have other issues. maybe a bad fuel connector. ...most fuel pump issues only show up when running WOT or high RPMs, generally will pump enough fuel to idle even if bad..disconnect fuel line going to carbs and turn motor over see if fuel pulses out of line it will not flow evenly but come out in spurts..connect a piece of fuel line long enough to get fuel away from motor for safety.

 

[Chris1956]

Re: 115 hp VRO fuel pump issue?

You may have a small air leak in the fuel line. You might suspect the main strainer under the airbox, the water seperator or other filters, as well as any other joints in the fuel line.