Onan 4k generator carb question

[ninemmbill]

So I neglected my Onan 4k generator over the summer and now it wont start. I am sure that it is just the carburetor being gummed up.

Looking at my generator it has an extra rubber hose coming off the front of the carb that my replacement one doesn't have. None of the troubleshooting videos I see on youtube have that hose either. What is it for?

My carburetor


new carb

[powercat_ras]

My 2015 production Onan 4000 W Gas Generator has a carb that looks like the one you purchased for replacement.

How old is the generator you are servicing ?

[ninemmbill]

It is a 2011 model

[Skip3370]

Why not take your gummed up carb to a reputable carb shop and have it cleaned instead of replacing it?

[aether_one]

I can't believe a carb gummed up just because you didn't use it for the summer.

That being said you van see the plug for the "extra" connector on the new carb. I suspect the connector on the "extra" hose just unscrews from the old carb and will screw into the new carb once the plug is removed.

It is probably a fuel recovery hose in case the float/needle valve stick and tries to overflow the bulb. Is the old carb a California carb?

[ninemmbill]

I did purchase the RV in California.

The port on the new carb isn't threaded at all, so I'm not sure it will screw in.

Well the generator wont start, it is getting fuel and the spark is good. I was going to put the new carb on and see if I could get the old one cleaned up.

[powercat_ras]

Think I would get your exact model and serial # and contact Onan customer support along with the # of the replacement carb you purchased. I suspect that they will tell you you bought the wrong one for your particular year model and serial #.

[A32Deuce]

Since you bought in California, you could just plug that hose and be done with it. Its for CAlifornia emissions.

[okcnewbie]

These carbs cause all kinds of problems and are generally not rebuildable.

[ninemmbill]

Thanks for all of the responses.

I do have an email request in to Onan, I will see what they say.

[Jim.B1]

Had a similar situation on a previous RV and the mechanic said the genny was dead and quoted a $4,000.00 repair job.
Another RV mechanic recommended spraying a product called Fire Up directly into the carb and it eventually started.
This was followed up by adding 2 bottles of Injector Cleaner into the fuel tank and running the genny.
The genny ran great for the next 7 years until sold.
Total expense was under $20.00.
At the end of each season, I add 1 bottle of Stablizer into the fuel tank and run the genny for 15 minutes.
Good luck.

[okcnewbie]

I agree with spraying whatever will work into the carb and allowing it to work. Sometimes that will not work for whatever reason.