Onan Generator Carb question

[Burn-in-RV]

Hello RV'ers
I am in need of your help,
1995 Coachman, low miles under 25k, just picked it up in the beginning of the summer & used it several times. It sat by our warehouse for almost 2 years not moved at all, the owner of the warehouse gave me a good deal.

Now its parked at our Cottage for a couple of weeks.
Kids wanted to sleep in it & the generator worked but died.

Replaced the battery, replaced the fuel pump which was an after market 12 volt unit, got fuel it starts but sounds like its missing a cylinder & blue black smoke is coming out of the exhaust.
pulled the plugs & they are tar black.
I am running super unleaded since i bought it to keep everything clean so i thought.
It wont accelerate but will die if you touch the throttle.

I called the dealer for parts & the only thing in stock is a coil pack & other odds & ends. Carb is back order #146-0749. Does anyone have any contacts for this carb?

Any suggestions?

Thanks Everyone!

[STBRetired]

Lots of parts are available through Amazon.

[darsben1]

Burn-in-RV wrote:
Will do once i am back up north taking apart.
hopefully have an answer in a week or so.

thanks for all your help.
Any of you got a parts guys to order parts for these?

thanks

I have ended up ordering direct from Cummins unless the parts place has the item in stock.

[Burn-in-RV]

Will do once i am back up north taking apart.
hopefully have an answer in a week or so.

thanks for all your help.
Any of you got a parts guys to order parts for these?

thanks

[Matt_Colie]

Find an older small engine shop and take him the carburetor. It is probably a Wahlboro and he will know how to clean it. He can also show you were to adjust it to get it right again.

Matt

[azrving]

theoldwizard1 wrote:
Additives or simple soaking are NOT a "sure cure". Best solution is remove the carburetor, disassemble and then soak overnight. Some people swear by soaking in hot water and Dawn dish washing liquid in an ultrasonic cleaner.

rjxj wrote:
We dont know you model number but some of them are 3.5 to 5 psi.

CONCUR !

My gut tells me the fuel pump is providing too much pressure.

Usually we hear about carb problems and the crud that is in them causing a lean condition with surging etc. If it's crud in the needle it seems he might experience flooding with fuel running out of the carb.

[theoldwizard1]

Additives or simple soaking are NOT a "sure cure". Best solution is remove the carburetor, disassemble and then soak overnight. Some people swear by soaking in hot water and Dawn dish washing liquid in an ultrasonic cleaner.

rjxj wrote:
We dont know you model number but some of them are 3.5 to 5 psi.

CONCUR !

My gut tells me the fuel pump is providing too much pressure.

[azrving]

We dont know you model number but some of them are 3.5 to 5 psi.

[Burn-in-RV]

Thank you everyone,
I will look at the one purchased from Auto zone 12 volt pump,
I will take gas line & check the measurement of fuel.
What is the fuel pressure need to be at? this will give me reference to the one i purchased.

I definitely like the sea-foam gas can idea..I will try that the next time i am up there.

Wow thanks to all who have had more Burn in time than i to figure these out!!

[midnightsadie]

you need more than a quarter tank fuel or some gen won,t run.

[4x4van]

Yup, Onan carbs are notorious for gumming up if let sit too long. As rjxj said, make sure you installed a low-pressure fuel pump. If it will run, drop the fuel line into a separate fuel tank/jug with a bottle of Seafoam mixed into the gas (one bottle in 5 gallons). Stuff will sometimes work wonders on gummed up carbs.

[darsben1]

Burn-in-RV wrote:
Thank you, So i am guessing that the carb is the problem since it sat so long?

Keep you posted.

It usually is

[azrving]

If you have the wrong fuel pump with too high a fuel pressure it could run very rich. Usually it would be black smoke but you did say black plugs and not oil wet plugs so it could be over rich. Some of the oem pumps are very low pressure but they all should produce volume and fill a pop bottle rather quickly. Maybe 15 seconds not minutes.

If you know the delivery is good then move on to carb etc

[Burn-in-RV]

Thank you, So i am guessing that the carb is the problem since it sat so long?

Keep you posted.

[wanderingaimles]

If you have a local small engine shop with a hydrosonic parts cleaner, have them put the carb in it for an hour, can frequently save from having to rebuild that way.