# Onan Generator fuel problem



## 4x4grey88

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?


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## JimE

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.


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## kg5388

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


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## Kirk

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.


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## kg5388

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


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## s.harrington

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.


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## Bill Haas

Onan Generator fuel problem

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

Thanks


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## kg5388

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


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## ARCHER

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.


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## Kirk

Onan Generator fuel problem

Author  Topic    
4x4grey88




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


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## kg5388

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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