Generator starts but won't run

txtinman

Well-known member
My 1 month old Onan gas generator, model #5.5HGJAB, will only start if I hold the butterfly valve closed. When I release the butterfly valve it goes full open and the motor dies. I have 10 gallons of fresh gas in the tank. I've talked to the people at Cummins and they directed me to a service center that's too far away for me to go to at this time. Any Ideas on how to fix it?

Mike
 

LBR

Well-known member
My 1 month old Onan gas generator, model #5.5HGJAB, will only start if I hold the butterfly valve closed. When I release the butterfly valve it goes full open and the motor dies. I have 10 gallons of fresh gas in the tank. I've talked to the people at Cummins and they directed me to a service center that's too far away for me to go to at this time. Any Ideas on how to fix it?

Mike
Go to YouTube and search "Onan, Seafoam." It will bring most dead or dying gennys back to life with a little patience and pampering.
 

Mikec91

Member
Find the oil level sensor and unplug it to see if it will stay running with that being said make sure your oil level is good

Sent from my SAMSUNG-SM-G930A using Tapatalk
 

txtinman

Well-known member
Find the oil level sensor and unplug it to see if it will stay running with that being said make sure your oil level is good

Sent from my SAMSUNG-SM-G930A using Tapatalk
My oil level is good, but I'm not sure where the oil level sensor is located. I don't find it in the manual.
 

carl.swoyer

Well-known member
My 1 month old Onan gas generator, model #5.5HGJAB, will only start if I hold the butterfly valve closed. When I release the butterfly valve it goes full open and the motor dies. I have 10 gallons of fresh gas in the tank. I've talked to the people at Cummins and they directed me to a service center that's too far away for me to go to at this time. Any Ideas on how to fix it?

Mike
Have you checked for any stored codes. ?

Sent from my XT1254 using Tapatalk
 

carl.swoyer

Well-known member
I g

et the 3-6 code.
If it is brand new I would look for a kink in the fuel supply line. Another one to look into, is there a fuel shut off. You can also disconnect the fuel supply line and take a fuel sample look for clairty. Drain the fuel into a clear jar and then spin/swirl the fuel and hold and inspect for any foreign matter. With the fuel line disconnected cycle the Onan generator and see if you have sufficient flow.

Sent from my XT1254 using Tapatalk
 

txtinman

Well-known member
I'm pretty sure it's a carburetor issue. I don't have the means to take it apart right now, so I'll wait until we get home to Alabama at the end of the month. I am trying to clean it out with Seafoam and I still might get it going. I'll post back on what happens. Thanks for all of the ideas and suggestions.

Mike
 

carl.swoyer

Well-known member
I'm pretty sure it's a carburetor issue. I don't have the means to take it apart right now, so I'll wait until we get home to Alabama at the end of the month. I am trying to clean it out with Seafoam and I still might get it going. I'll post back on what happens. Thanks for all of the ideas and suggestions.

Mike
If you're able put it right in the fuel supply line. Disconnect it at the carb and put some in.
Am I mistaking or isn't the generator new

Sent from my XT1254 using Tapatalk
 

txtinman

Well-known member
If you're able put it right in the fuel supply line. Disconnect it at the carb and put some in.
Am I mistaking or isn't the generator new

Sent from my XT1254 using Tapatalk
Yeah it's new. We started it at the walk-thru inspection. I've been at the camp ground for a month
and haven't started it. I don't think I should be having problems already, but I'm not really surprised either.

Mike
 

carl.swoyer

Well-known member
I'm pretty sure it's a carburetor issue. I don't have the means to take it apart right now, so I'll wait until we get home to Alabama at the end of the month. I am trying to clean it out with Seafoam and I still might get it going. I'll post back on what happens. Thanks for all of the ideas and suggestions.

Mike
Before tearing the carburator apart take a fuel sample from the feed line and the bowl. This should demonstrate good or bad fuel. While you have the fuel line disconnected cycle the generator to see if you have adequate fuel supply. If you have good fuel and good supply well then possibly a clogged fuel filter. Simply things before tearing up the carb is my suggestion.

Sent from my XT1254 using Tapatalk
 

txtinman

Well-known member
Before tearing the carburator apart take a fuel sample from the feed line and the bowl. This should demonstrate good or bad fuel. While you have the fuel line disconnected cycle the generator to see if you have adequate fuel supply. If you have good fuel and good supply well then possibly a clogged fuel filter. Simply things before tearing up the carb is my suggestion.

Sent from my XT1254 using Tapatalk
Good idea. I don't want to tear into it unless I have to.

Mike
 

porthole

Retired
Yeah it's new. We started it at the walk-thru inspection. I've been at the camp ground for a month
and haven't started it. I don't think I should be having problems already, but I'm not really surprised either.

It takes less then a month for the current fuel available to start going bad.

Good idea. I don't want to tear into it unless I have to.

If you decide that route, do so carefully, rebuild kits are no longer available thanks to the EPA.

Did you look at the link I posted above on the codes and the fuel shut off solenoid?
 

txtinman

Well-known member
It takes less then a month for the current fuel available to start going bad.



If you decide that route, do so carefully, rebuild kits are no longer available thanks to the EPA.

Did you look at the link I posted above on the codes and the fuel shut off solenoid?
I did, thanks for the info. I rapped on the solenoid, but it didn't make a difference.

I have it at the point that it will run by itself until it warms up. At that point the choke is fully open and the motor shuts down. Possibly a fuel flow problem.

Mike
 

porthole

Retired
I did, thanks for the info. I rapped on the solenoid, but it didn't make a difference.

I have it at the point that it will run by itself until it warms up. At that point the choke is fully open and the motor shuts down. Possibly a fuel flow problem.

Mike


The solenoid has a metal gasket. You could try removing it, see if the plunger is free. Try spraying carb cleaner up into the port. Spray the solenoid plunger as well.


Unfortunately, with modern, small, carbureted engines, the EPA and emission requirements have taken it's toll of drivability.
Fuel quality and degradation of the fuel does not help.
These engines run so lean they are on the border of not running if the slightest piece of debris gets in the fuel system.

Seafoam may help, but it is only a bandaid "mechanic in a can" approach.

If and when you get it running, a good best practice would be to religiously use a fuel and ethanal stabilizer every time you put gasoline in the tank.

On ours I would pump all the fuel into our car at the end of the season, fill with fresh fuel and stabilizer for the winter. Frequently one of our earlier trips of the year was to a NASACR race so I was able to burn all the fuel that was stored for the winter fairly early in the season.
 

carl.swoyer

Well-known member
The solenoid has a metal gasket. You could try removing it, see if the plunger is free. Try spraying carb cleaner up into the port. Spray the solenoid plunger as well.


Unfortunately, with modern, small, carbureted engines, the EPA and emission requirements have taken it's toll of drivability.
Fuel quality and degradation of the fuel does not help.
These engines run so lean they are on the border of not running if the slightest piece of debris gets in the fuel system.

Seafoam may help, but it is only a bandaid "mechanic in a can" approach.

If and when you get it running, a good best practice would be to religiously use a fuel and ethanal stabilizer every time you put gasoline in the tank.

On ours I would pump all the fuel into our car at the end of the season, fill with fresh fuel and stabilizer for the winter. Frequently one of our earlier trips of the year was to a NASACR race so I was able to burn all the fuel that was stored for the winter fairly early in the season.
Personally, if I had a gas generator I would only use Marine grade fuel.


Sent from my XT1254 using Tapatalk
 

porthole

Retired
Personally, if I had a gas generator I would only use Marine grade fuel.


I have that option, we live near multiple marinas. Valvtect fuel is gasoline with Valvtect additives.

Also means we are close to multiple West Marines, which have all the marine related additives, including Seafoam.
 
Top