Generator/starting fluid/carb questions

[BikerRN1]

Hi. I slipped on maintenance, had my carbon 33 skirted for the winter and didn't start my onan 4000 for 5 months. Had a mobile repair guy come check it when it wouldn't start, he says bad gas, replace carb. It ran fine when he squirted started fluid in the aircleaner. Prior to his arrival, i siphoned all the gas out (smelled like gas to me, I had stability in it in appropriate amount and it was not dark or thick) and put 2 gallons ethanol free 89 octane in tank. Is that enough fuel? I have read that they need 1/4 tank to run, but I guess I thought that was for motorhomes so they would not run out of fuel. Suggestions? I really cannot afford a new carb right now.

[twinboat]

There is a treatment routine that uses Seafoam to clean the carburator.

Here is a link

https://seafoamworks.com/questions-a...uretor-solved/

[donr103]

Did you get old carb back? I bet tech kept your old carb right ?
1st pull fuel line at carb and use empty pop bottle to catch any gas and see if you can get steady stream..
2nd.. while someone is cranking.. put your hand on f/P and see if vibration..
10mins and free..
Good luck and keep us posted

[fcbbob15]

As twinboat says the carb can be cleaned. I have done it myself. I used Berryman B12 carb cleaner spray. You need to take the carb apart to clean it. I used compressed air and torch tip cleaners to clean the small orifices.

[BikerRN1]

No, he said 600 for a carb and 4 hrs labor at 100/hrs to change it out. I can't see a grand for a carb so nothing has been done at this time

[08Carriage]

A new carb for Onan 4000 on Amazon is less than $50.00 for most.
I would add a shutoff valve for the gas
Run the carb dry after use before long storage no more problems

[Wrapped]

Get can of carb cleaner spray until generator starts before it dies spray again, keep doing this for 30/40 seconds, don't let generator stop,get gas upto fuel pump ,may have lost prime. If that doesn't work pull fuel line off carb, attach longer hose to carb put funnel in other end of hose hold above carb pour some gas in funnel to gravity feed fresh gas to carb and start,if this works its bad pump.

[jacwjames]

Originally Posted by twinboat

There is a treatment routine that uses Seafoam to clean the carburator.

Here is a link

https://seafoamworks.com/questions-a...uretor-solved/

My brother does small engine repair and highly recommends Seafoam, I use it now


The carburetor has tiny orifices and needle valves. When the gas gums up these get plugged. Sometimes you can take a carb out and clean it others times you have to replace. If you can get a carb it would be cheaper then having someone try and fix it.

I let my chainsaw sit and the carb gummed up, took apart and cleaned but could get it to run. New carb ~$20.

[jacwjames]

Originally Posted by 08Carriage

A new carb for Onan 4000 on Amazon is less than $50.00 for most.
I would add a shutoff valve for the gas
Run the carb dry after use before long storage no more problems

This is also good advice, fuel cut off, run fuel out of system and carburetor. You can also buy some fogging spray to used when you winterize. They do that to Outboard motors all the time.



I'd remove the old carb and try and clean first as some of the previous posts suggest. If not do a search for a replacement carb, doesn't have to be OEM.

[ArtJoyce]

Originally Posted by twinboat

There is a treatment routine that uses Seafoam to clean the carburator.

Here is a link

https://seafoamworks.com/questions-a...uretor-solved/

That is my goto when things will not start or run poorly in the spring. I have taken apart my share of carbs to clean with carb cleaner.

I try to run the carbs dry before putting away for the season

[ArtJoyce]

Originally Posted by BikerRN1

Hi. I slipped on maintenance, had my carbon 33 skirted for the winter and didn't start my onan 4000 for 5 months. Had a mobile repair guy come check it when it wouldn't start, he says bad gas, replace carb. It ran fine when he squirted started fluid in the aircleaner. Prior to his arrival, i siphoned all the gas out (smelled like gas to me, I had stability in it in appropriate amount and it was not dark or thick) and put 2 gallons ethanol free 89 octane in tank. Is that enough fuel? I have read that they need 1/4 tank to run, but I guess I thought that was for motorhomes so they would not run out of fuel. Suggestions? I really cannot afford a new carb right now.

It sounds like the gas dried up in the carb and cloged the jets or flot.

[SergioP]

My generator was hard to start, requiring 2 or 3 times to get it to run. Then running, it would surge. I found a video on YouTube on how to remove and clean the carb. Cleaned it and it works fine now.

It wasn’t difficult to remove, just be careful disassembling the solenoid there’s crush washers between the 2 or 3 pieces. Maybe take a couple pictures of it before taking it apart.

https://youtu.be/Ph_C6XF2TCU

[donr103]

If ran and started on starting fluid.. I would lean more towards bad f/p or cracks in old rubber fuel line. Or even bad f/p ground or electric wires or fuse.. . 1st do f/p check.. then that swill narrow it down fast..
Yes most carbs can be easily cleaned.. try never to replace...
It could be bad fuel hose.. they can be pinched where they run from main tank to f/p.. or alcohol in gas can eat insides.. critters eat outsides of hoses and if hose is older than 5 yrs... hoses can get fine cracks that leak air.. but strangely enough.. don't leak fuel..
Once you test f/p get back to us.. there is even easier way to clean carb.. while on gen and takes 30mins.. or less and you just need one 5.00 spray can of carb cleaner
Good luck and keep us posted

[BikerRN1]

Thanks to all, will report when I have time to work on it.