Onan 5500 Problems

Okay guys, new problem.

I put a new carb on it and it fired up. Ran it for about 10 minutes, no problems at all. Shut it down and now it won't fire back up. It will light off, but as soon as you turn loose of the start button it dies.
Edit - Okay, I let it sit for 10-15 minutes and it fired back up. Is it possible this thing is flooding itself out when it shuts down?

Thoughts?


Did it kick any codes?

- - - Updated - - -

Yeah, I'd love to see some pics of the housing mod, just as general FYI.

Here you go, I have a video if you want to see it, PM me and I will try to send it to you that way.
 

Attachments

  • Cover removed front.jpg
    Cover removed front.jpg
    4.7 MB · Views: 27
  • Cover removed.jpg
    Cover removed.jpg
    5.4 MB · Views: 28
  • Door lip.jpg
    Door lip.jpg
    5.4 MB · Views: 26
  • Front Cover.jpg
    Front Cover.jpg
    2.3 MB · Views: 32
  • Inside left.jpg
    Inside left.jpg
    2.1 MB · Views: 31
  • Inside Right.jpg
    Inside Right.jpg
    2.2 MB · Views: 39
  • Regulator end.jpg
    Regulator end.jpg
    3.1 MB · Views: 26

TerribleTim68

Well-known member
No clue on the codes. Don't know where to look for them, or have anything that would read them if it did.

Anyways, the end result was, with the new Chinese carb from the Amazonians it ran all day long on Thursday, probably about 8 hours, then fired up again Friday and ran for another 12 hours, then fired up again Saturday and ran for another solid 10 hours, then fired up again Sunday and ran for a solid 7 hours. All of that was with a fairly heavy load on it in some form of either the AC running non-stop, me running a commercial smoker, me running a commercial cook-and-hold oven or some combo of those items at the same time. Basically I turned it into a giant mobile catering rig while running the AC. I had to feed about 30 volunteers for 4 days.

I still have no clue how big that fuel tank is, but it was full when we started this adventure, I dumped another 5 gallons in it Friday and it was down to just above a 1/4 tank when I shut it down Sunday afternoon. I call it a success. Now here's to hoping I don't need to replace the carb every season.

Oh, the one thing I did notice was that every morning when I tried to start it, it would do that thing where it starts and immediately dies. You'd do that a couple three times, then let it sit for 5 minutes or so and then try again and it would fire right up. And it still wouldn't fire up right after being shut down. I'm really leaning toward it flooding itself on shut-down. But no clue on the first startup each morning.
 

avvidclif

Well-known member
When cold starting mine I use the prime button several times before starting and it doesn't have any problems.
 

TerribleTim68

Well-known member
When cold starting mine I use the prime button several times before starting and it doesn't have any problems.
Yeah, it didn't seem to matter if I primed it first or not. It still did the same thing. I just figured "okay fine, do this procedure, then let it sit for 5-10 minutes and try again", worked every time so I just went with it. Sometimes you have to let the thing tell you how it will work and just accept it. :D
 

porthole

Retired
Hey guys,
Figured I'd better fire up the generator before our big outing this week. Wouldn't you know it, it won't run. :(


Did you see my link for the Onan run problems and possible solutions?

Link below.

I also have genuine Onan parts listed in the for sale section. 2 of those parts are a carb and the fuel solenoid.
 

ChaSue

Member
Having problems with our Onan 5500. Ran great for 2 days. 3rd day started surging. Let it run for about 1 hour never ran smooth. Inside fuel gauge isn't reading properly, stuck on full. Does anyone know what the tank capacity is on a 2019 Cyclone 3600?
 

WillyBill

Well-known member
Having problems with our Onan 5500. Ran great for 2 days. 3rd day started surging. Let it run for about 1 hour never ran smooth. Inside fuel gauge isn't reading properly, stuck on full. Does anyone know what the tank capacity is on a 2019 Cyclone 3600?

30 gal if one tank. Second tank is 20 and if you have a second it is dedicated to gen only and the 30 is not connected to the gen at all.

Good Luck!

WB
 

Tool958

Well-known member
Having problems with our Onan 5500. Ran great for 2 days. 3rd day started surging. Let it run for about 1 hour never ran smooth. Inside fuel gauge isn't reading properly, stuck on full. Does anyone know what the tank capacity is on a 2019 Cyclone 3600?

Ours was doing this. I ran a good dose of Seafoam through the generator and cleared it up. I also add Stabil in every fill up. Between the two, seems to have cured the problem for now.


Sent from my iPad using Tapatalk Pro
 

LBR

Well-known member
I have a reminder in my phone calendar...'Onan' on the first day of every month. Am running it now for it's monthly workout.
 

WillyBill

Well-known member
One last item to check - the vent in the fuel cap - if the gen sucks a vacuum it will die after a few minutes or worse.

WB
 

carl.swoyer

Well-known member
I have to admit I didn't read the entire post .
That being said I have an lp 5500 Onan therefore I don't worry about remembering to run the generator.
I wonder if anyone with the the gas generators have considered using Marine grade fuel ?
It doesn't have the issues that gas with ethanol has. Better performance and last alot longer without breaking the bank.

Sent from my moto z3 using Tapatalk
 

WillyBill

Well-known member
I have to admit I didn't read the entire post .
That being said I have an lp 5500 Onan therefore I don't worry about remembering to run the generator.
I wonder if anyone with the the gas generators have considered using Marine grade fuel ?
It doesn't have the issues that gas with ethanol has. Better performance and last alot longer without breaking the bank.

Sent from my moto z3 using Tapatalk

We run 100% non ethanol gas in ALL our toys and small engines - no fuel related problems in anything! YEA!

WB
 
Top