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Onan RV QG 5500 won't start

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****,  I know this has been discussed in the past.  I've read most that I have found but......

Onan RV QG 5500... it sat over a year.  It cranks when start button is pushed.  What I've done:

New plugs. Confirmed fuel pump is working.  Primed bowl and checked fuel by draining it from bottom of the bowl, it's clean.  Tried carb cleaner. Tried compressed air to clear any debris.  Fully charged batteries and made sure connections are clean and tight. Air filter is new and clean. Oil is clean and topped off. 

Now, when I try starting fluid it starts right up and runs till the starting fluid is gone, but it will not start otherwise.  It just cranks.

It has just over 100 hours on it.

Any other ideas???  Thanks so much!

 

20191210_113204.jpg

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Does the blinking light give you a code? Is oil full? Have you used an Onan oil filter or SOB?

It looks like your altitude setting is at 5000 feet. Is that your current elevation?

If so equipped  be sure to prime the start toggle until the light goes out then press to start.

Try turning off both 20 and 30 circuit breakers on the generator and see if it will start and continue.  If it does let it warm up and turn the breakers back on one at a time.

Agree on the old gas.  If not stabilized a year ago you will need to start with fresh gas.

 

Edited by rockylarson
agree x1

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1 hour ago, Bvbh said:

when I try starting fluid it starts right up and runs till the starting fluid is gone,

You certainly have a fuel issue. Could be aerated fuel, could be a clog internally within the carburetor. 

Just tossing this out there, it is full of oil correct? I see a low oil level sensor in the photo.

Try and give it a different fuel source and see if it starts. Unhook the fuel line, and pick up some bulk fuel hose, drop it into a gas can and see if it runs.

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It could the carb.  If fuel was not treated and is old chances are you have a plugged oriface.  When we were an Onan dealer it was less expensive to replace the carb with a new one  than to try to repair the old one.  Success rate was less than 50% and with the cost of labor It made a better choice.

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Sound like you just need an old fashion carburetor cleaning. Those carburetors are simple, just dissemble, remove all jets, float and needle valve. soak overnight in carburetor cleaner(or place in ultrasonic cleaner) blow out all passages and you are good to go. 

If you are a novice just got to YOU TUBE and you will become a pro.

Jim

Quote

 

 

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3 hours ago, F433921 said:

Sound like you just need an old fashion carburetor cleaning. Those carburetors are simple, just dissemble, remove all jets, float and needle valve. soak overnight in carburetor cleaner(or place in ultrasonic cleaner) blow out all passages and you are good to go. 

If you are a novice just got to YOU TUBE and you will become a pro.

Jim

 

The Onan carb does not come apart like a normal carb.  For the most part its pressed together and you destroy it if you take it apart.  We were in that business  for some 20 years with hundreds of carbs experiences.
W

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8 hours ago, Bvbh said:

****,  I know this has been discussed in the past.  I've read most that I have found but......

Onan RV QG 5500... it sat over a year.  It cranks when start button is pushed.  What I've done:

New plugs. Confirmed fuel pump is working.  Primed bowl and checked fuel by draining it from bottom of the bowl, it's clean.  Tried carb cleaner. Tried compressed air to clear any debris.  Fully charged batteries and made sure connections are clean and tight. Air filter is new and clean. Oil is clean and topped off. 

Now, when I try starting fluid it starts right up and runs till the starting fluid is gone, but it will not start otherwise.  It just cranks.

It has just over 100 hours on it.

Any other ideas???  Thanks so much!

 

20191210_113204.jpg

Thinking the fuel supply solenoid is not working. It is the silver looking unit,that has the 2 white wire plug and is screwed into the altitude adjustment.  The solenoid valve seat is stuck in the seat. Remove it and sock the threaded end in some  carburetor cleaner. With an ohm meter read the resistance  across the 2 pins.  

When you try to start the engine do you read 12 volts between the 2 pins that connect to the solenoid?

Rich. 

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