Onan Generator fuel problem

Discussion in 'Beginning RVing' started by 4x4grey88, Mar 27, 2006.

  1. 4x4grey88

    4x4grey88 New Member

    Recently purchased a Pace Arrow (1985). I attempted to run the generator to no avail. It cranks over and has spark. I removed the fuel hose and found it bare dry.

    So, here is my question....

    Does the Onan generator have built in fuel pump or is it external?

    I will tell you this; I jumped a hose (from a gas can) to the inlet of the carb (after the fuel filter and some kind of sensor, or what is believed to be a sensor {or could be the internal fuel pump}) and she ran, but like she was starving for fuel and cycles allot. So I know that the generator will run but not correctly.

    Does the fuel line connect to a fuel pump under the fuel filter? or is it suction or external pumped?
     
  2. JimE

    JimE Senior Member

    Onan Generator fuel problem

    Is the fuel tank on the motorhome full? When your fuel tank hits 1/4 of a tank, your generator will be dry. Its a failsafe to make sure you dont run out of gas running the generator.
     
  3. kg5388

    kg5388 New Member

    Onan Generator fuel problem

    how about a model number for the genset
    if it is a 4.0 ky microlite that is a fuel shutdown solinoid on the bottom of the carb the fuel pump is under the control board with the starter solinoid mounted on top
    make sure the fuel lines from the rv tank to the genset does not have any holes or dry rot because if if can suck air the fuel pump will not prime
    try hooking your fuel can to the genset inlet underneath and see if it will prime you should hear the fuel pump knock until it primes
     
  4. Kirk

    Kirk Senior Member

    Onan Generator fuel problem

    In 1985 I believe the Onan had an electric fuel pump that was mounted on the side of the genset. At least my 4KW Onan did in 1987. The fuel line came from the tank to the pump which was mounted on the front of the genset and looked like a vertically mounted cylinder. To check it you would have to break the line between it and the carburetor.
     
  5. kg5388

    kg5388 New Member

    Onan Generator fuel problem

    thats right kirk thats why a MODEL number is so important the gensts with that style of fuel pumps are NH , NHE , NHM , BGE and BGM and the models with the fuel pumps under the control starting in the early 90 are the KVC , KV and the KY
    it's hard to go by the year of the rv because of refits and change outs by different owners
     
  6. s.harrington

    s.harrington Senior Member

    Onan Generator fuel problem

    He probably has a BFA or BGE model if it a 4.0kw and the fuel pump is under the carburator. Its the round tall model with the built in fuel filter at the bottom. Hoever the first thing he should do is check and see if the gas hose is any good. One that old would have rotten rubber hose by now. Just blow through the hose tword the tank. it should be like blowing through a straw into your soda. You should feel a bubble type back pressure. Also pull the bottom off the pump and see if the filter screen in plugged. Then test the pump. Put a short rubber hose on the inlet and drop it into a gas can and hit the start button. you should get gas through the pump.
     
  7. Bill Haas

    Bill Haas New Member

    Onan Generator fuel problem

    Ok, on the BGE Onan 4.0K gas geneerator where is this fuel hose located ?

    Thanks
     
  8. kg5388

    kg5388 New Member

    Onan Generator fuel problem

    on a BGE look at the carb and follow the metal fuel line across the top of the box where the start switch is and it will lead you to the round or square fuel pump down on the right hand side and the barbed hose fitting on the bottom is where the rubber fuel line goes unless someone has put an after market fuel pump on that is not an onan part
     
  9. ARCHER

    ARCHER Senior Member

    Onan Generator fuel problem

    Probably also all GUMMED up from sitting and not being ran. Need to run those things monthly at least 30 minutes to keep the lines clean, etc. Also, annually new plug(s), fuel filter, air filter, oil change, etc. Had one that had to be rebuilt due to non-use.
     
  10. Kirk

    Kirk Senior Member

    Onan Generator fuel problem

    Author Topic
    4x4grey88




    USA
    7 Posts
    Posted - Mar 27 2006 : 02:36:39 AM
    --------------------------------------------------------------------------------

    Recently purchased a Pace Arrow (1985). I attempted to run the generator to no avail. It cranks over and has spark. I removed the fuel hose and found it bare dry.

    So, here is my question....

    Does the Onan generator have built in fuel pump or is it external?

    I will tell you this; I jumped a hose (from a gas can) to the inlet of the carb (after the fuel filter and some kind of sensor, or what is believed to be a sensor {or could be the internal fuel pump}) and she ran, but like she was starving for fuel and cycles allot. So I know that the generator will run but not correctly.

    Does the fuel line connect to a fuel pump under the fuel filter? or is it suction or external pumped?


    JimE




    26 Posts
    Posted - Mar 27 2006 : 08:32:28 AM
    --------------------------------------------------------------------------------

    Is the fuel tank on the motorhome full? When your fuel tank hits 1/4 of a tank, your generator will be dry. Its a failsafe to make sure you dont run out of gas running the generator.

    --------------------------------------------------------------------------------
    Jim
    1993 31' Winnebago Brave


    kg5388




    8 Posts
    Posted - Mar 27 2006 : 6:52:10 PM
    --------------------------------------------------------------------------------

    how about a model number for the genset
    if it is a 4.0 ky microlite that is a fuel shutdown solinoid on the bottom of the carb the fuel pump is under the control board with the starter solinoid mounted on top
    make sure the fuel lines from the rv tank to the genset does not have any holes or dry rot because if if can suck air the fuel pump will not prime
    try hooking your fuel can to the genset inlet underneath and see if it will prime you should hear the fuel pump knock until it primes


    Kirk




    USA
    771 Posts
    Posted - Mar 29 2006 : 11:01:09 PM
    --------------------------------------------------------------------------------

    In 1985 I believe the Onan had an electric fuel pump that was mounted on the side of the genset. At least my 4KW Onan did in 1987. The fuel line came from the tank to the pump which was mounted on the front of the genset and looked like a vertically mounted cylinder. To check it you would have to break the line between it and the carburetor.

    --------------------------------------------------------------------------------
    Good travelin! ......Kirk
    www.1tree.net/adventure

    sent via Starband, tirpod mount internet dish


    kg5388




    8 Posts
    Posted - Mar 29 2006 : 11:47:26 PM
    --------------------------------------------------------------------------------

    thats right kirk thats why a MODEL number is so important the gensts with that style of fuel pumps are NH , NHE , NHM , BGE and BGM and the models with the fuel pumps under the control starting in the early 90 are the KVC , KV and the KY
    it's hard to go by the year of the rv because of refits and change outs by different owners


    s.harrington




    USA
    197 Posts
    Posted - Apr 23 2006 : 01:08:34 AM
    --------------------------------------------------------------------------------

    He probably has a BFA or BGE model if it a 4.0kw and the fuel pump is under the carburator. Its the round tall model with the built in fuel filter at the bottom. Hoever the first thing he should do is check and see if the gas hose is any good. One that old would have rotten rubber hose by now. Just blow through the hose tword the tank. it should be like blowing through a straw into your soda. You should feel a bubble type back pressure. Also pull the bottom off the pump and see if the filter screen in plugged. Then test the pump. Put a short rubber hose on the inlet and drop it into a gas can and hit the start button. you should get gas through the pump.

    --------------------------------------------------------------------------------
    S. Harrington
    All American RV Services
    www.aarvservices.com
    www.spartanhauler.com


    Bill Haas




    1 Posts
    Posted - May 04 2006 : 9:16:11 PM
    --------------------------------------------------------------------------------

    Ok, on the BGE Onan 4.0K gas geneerator where is this fuel hose located ?

    Thanks


    kg5388, do you know of a place to get service manuals for the Onans?
     
  11. kg5388

    kg5388 New Member

    Onan Generator fuel problem

    onan manuals can be ordered from your local onan distributor and even shipped to your house but you can get parts and manuals cheaper from http://www.funroads.com/onanstore/osHome.jhtml just don't tell my boss i told you
     

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