Onan generator fuel pump question

[Virago-Rider]

Onan BGE spec N.
Genset 5000

3/4 tank of fuel
New oil and filter
New flight systems control board
New fuel pump


The question is primarily about the fuel pump. Because of the almost impossible to reach location of the factory pump, I mounted this one in another location. I mounted it vertically rather than horizontal as the factory.

Does the orientation make a difference?

The generator runs but, RPMs are not steady. Slows down, almost stalls, the recovers... Over and over and over.

If the vertical orientation is not a problem, what do I need to check, adjust, tweak or smash with a BFH?

Thanks


🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[Virago-Rider]

The generator only has 310 hours on it.


🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[Waiter21]

It shouldn't make any difference on pump orientation, but the pump should be below the lowest level of the fuel tank to help prevent a vapor lock in the pump.

I'm not sure you can push fuel through the old pump???

One test you could do would be to remove the fuel hose off the carb, put it in a container, then turn the pump on to see how much fuel you deliver.

I've haven't done this, but another consideration if you're mounting the pump external, mount a filter external and then run a new hos from your new pump all the way to the carb. This would completely bypass the old pump and filter.

ALSO - Did you install a new spark plug, Might not hurt.

[Virago-Rider]

I have an inline filter before the pump and have bypassed the original pump and filter.....

Apparently previous owner had drilled out the original filter as you can see all the way through it.

Gen was running fine... Then one day, wouldn't run without holding the start button in.

After a few phone calls to flight systems.... They concluded it was the control board.... Ordered one.

Now, gen runs...... But, runs as described above.

I have emailed flight systems... But, no reply as of yet.. I guess once they had my money, I am no longer a priority.


🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[Virago-Rider]

And, yes, new spark plugs.
From what I am able to find, being a BGE spec N it has electronic ignition rather than points. However, it does have a condenser.... So that is a bit confusing.


🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[JRMEDPHYS]

I know you are thinking fuel pump because you have recently changed it out, but what you are describing could also be a dirty carb. I have had gas engines that surge like that if they had some junk or debris in the carb...which may be possible since you just changed the fuel pump/line/filter?

And this is under no load, right? (breakers switched off at the gennie)

[Virago-Rider]

No, with load.

I exercise the gen 1 hour under load twice a month... Itwas working fine until one day.....

It would only run while start button was pressed... After several dialogues with flight systems I was told that it was the control board.

Now, with the new board, it runs like crap.




🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[Virago-Rider]

I have a video, but can't seem to attach it to the message




🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[spyderRV]

From the manual.

Trouble Possible Cause Corrective Action
Engine 1. Sticking or binding 1. Clean governor linkage (remove dirt or
Surges (mechanical) governor linkage. ice buildup). Check that linkage
does not touch other parts.
2. Incorrect (mechanical) governor 2. Adjust governor speed and
adjustment. sensitivity.
3. Faulty (mechanical) governor 3. Replace governor spring.
4. Incorrect fuel mixture due to: 4a. Adjust carburetor main and
a. incorrectly adjusted idle adjustment screws.1
fuel mixture screws.1 4b. Adjust carburetor float level.1
* b. incorrect float level.1, 2 4c. Disassemble carburetor and
c. dirt in carburetor clean all internal passages.1
d. ignition misfires 4d. Check connections, see Ignition
section.
5. Intermittent electrical 5. Check battery and ignition connections.
connections.
6. Governor mechanism worn 6. See Engine Block
excessively. Assembly section.
7. Fuel supply problem caused by: 7a. Check fuel pump and replace
a. Faulty fuel pump.2 if defective.
b. Contaminated fuel supply.2 7b. Drain and refill fuel supply
c. Vapor locking.2 7c. Check for cause of overheating
d. Plugged fuel filter 7d. Replace fuel filter.
8. Carburetor icing.2 8. In cold weather, place air
preheater in winter position.

[JRMEDPHYS]

Originally Posted by Virago-Rider

No, with load.

I exercise the gen 1 hour under load twice a month... Itwas working fine until one day.....

It would only run while start button was pressed... After several dialogues with flight systems I was told that it was the control board.

Now, with the new board, it runs like crap.




🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

But does it run like crap under no load? You have changed a couple of things with the generator and I think you need to separate an engine problem from a generator section problem by confirming the engine runs just fine under no load. Just switch the breakers off on the genie itself and run the engine to see if it behaves the same way.

[Virago-Rider]

It is rough starting... But, once started it will run stable with no load


🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[Virago-Rider]

Update...

Changed nothing from two days ago...



Ok.... Got in from work, went out to the camper. Turned on batteries, fired up the generator... Stumbled and sputtered for a minute or so. Then smoothed out... Stable running no load.

Turned on 1 air conditioner... Everything fine.... Ran 40 minutes... Stable.. Voltage 126-128.

Turned on second are conditioner.... Gen lugged way down... AC volts dropped to around 100. Both ACs stopped due to low volts. In all the years we have owned this camper we could run both ACs on generator with no problems.

After both ACs shut down, voltage recovered to 127-128

After the short cycle circuit on the ACs timed out, I could run either one just fine. But, not both.

Very puzzling.

The service docs provided by SpyderRV a few posts up,....talked about adjustment of the governor. But, requires a frequency meter.... I don't have one.


Still in search of an answer

Thanks


🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

[wizechatmgr]

Originally Posted by Virago-Rider

Update...

Changed nothing from two days ago...



Ok.... Got in from work, went out to the camper. Turned on batteries, fired up the generator... Stumbled and sputtered for a minute or so. Then smoothed out... Stable running no load.

Turned on 1 air conditioner... Everything fine.... Ran 40 minutes... Stable.. Voltage 126-128.

Turned on second are conditioner.... Gen lugged way down... AC volts dropped to around 100. Both ACs stopped due to low volts. In all the years we have owned this camper we could run both ACs on generator with no problems.

After both ACs shut down, voltage recovered to 127-128

After the short cycle circuit on the ACs timed out, I could run either one just fine. But, not both.

Very puzzling.

The service docs talked about adjustment of the governor. But, requires a frequency meter.... I don't have one.


Still in search of an answer

Thanks


������
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum

If you have a tachometer you should see if she's slugging at the same time the AC volts drop. I'd be willing to bet this is still a carb issue. Do you treat the fuel with anything? How old is the fuel it is currently burning? Do you have an inline fuel filter before the carb? I'd also be tempted to remove the air filter while running for testing purposes.

[Virago-Rider]

Fuel is less than one month old 100% gas... No ethanol...

I treat every other tankful with Lucas ... Helps on fuel mileage a bit.

I have an inline filter just before the fuel pump... And I changed it just to be sure it wasn't the problem..


I don't have a tach... But, you can hear the generator's engine drop speed.


🚌🚍🚌
1998 Thor Windsport 33SL on 1997 F53 chassis.
2007 Chevy Uplander TOAD.
1985 Yamaha Virago XV700

Sent from my iPad2 using iRV2 - RV Forum