Onan 40KY Generator ; runs a bit then stalls

[HelloImDavid]

I soaked the carb in Berrymans Solvent in a can overnight then shook out the carb the next morning. Installed the carb . Fired it up by fiddling with the choke and got it to run about 15 seconds before it died . I messed with the throttle control screw toward the back of the Generator to no avail. So, im stuck now. Ive got gasoline in the float bowl and the fuel pump is new and rated at 2.5 - 4.0 psi . What can I try before having to take it in to a RV place ? Thanks a lot.

P.S. Is there a troubleshooting guide available for this Generator for such an issue ?

Dave
2008 Coachman Freedom Express Class C.

[HelloImDavid]

Thanks every one for responding. After some more putzin' , I got it to run pretty smooth. I think I just need to get all the Berrymens Solution out of the carb .

What should the generator be set at for voltage output ? Right now, im getting between 121-123 vac out of it .

Thanks again Folks. Dave.

[j-d]

We have OP "Generator Jim" who said the same thing about the 4KY carburetor - Idle passages we can't "tag wire" or get much of anything through if clogged. A few, GodBlessEm have been able to clean them up. Exception not the rule.

[Chris_Bryant]

If it is a micro quiet, replacement is the only answer. There are reportedly 90 degree passages that cannot be cleaned.

Fwiw, Seafoam is mostly diesel fuel, naphtha, and alcohol, Berryman b12 is mostly toluene and alcohol.

[johntank]

eHoefler wrote:
Actually take the carb apart and clean it properly, blow out all the passages and jets.

X-2

[Vulcan_Rider]

midnightsadie wrote:
VULCAN< your not right. and thats all I,ll say. we are marine dealer.

I don't care who or what you are.

I've been studying chemistry and physics and working on engines for about 50 years now and I am telling YOU that none of the ingredients in SeaFoam are good solvents for fuel deposits. They just aren't.
Do you even KNOW what is in the stuff ??

Will it work as a fuel system "cleaner" ?? Yes probably if the problem is not too bad.

There are other products that are much better. Fact.
SeaFoam is a jack of all trades and master of none.

But everyone is free to make his own choice.
My opinion of SeaFoam is that it is high priced snake oil.

[Chris_Bryant]

The first thing I do when working on a generator with fuel problems is to hook it to an external tank- too many cracked fuel lines out there. This way you know what you are working with, plus you can easily treat the fuel with cleaner.

And- I use Seafoam as well- it has yet to let me down.

[midnightsadie]

VULCAN< your not right. and thats all I,ll say. we are marine dealer.

[Vulcan_Rider]

midnightsadie wrote:
berry,s is ok,I guess, but to eat up gunk use sea foam,

SIGH. Here we go again.

SeaFoam does a great job......of MARKETING.
Originally formulated as a marine fuel stabilizer, other "recommended" uses are a stretch. It works as a light duty cleaner; for really bad cases it's just not up to the task.

Berrymans B12 Chemtool and Gumout are MUCH better cleaners but for anything to work you must get it into the tiny little passages that clog first. Often just soaking, in anything, won't do that.

[Golden_HVAC]

I have found that a cold engine will start and run- even if the carb is running really rich, but will stall once warm. The stuck float or leaking float that allows in to much fuel can cause it to run really rich.

Replacing the carb is 'throwing parts at it' but if the choice is to spend $300 on the RV repair shop, or throw a part at it, you might as well make that decision. The RV place might say it needed a new carb, charge you $300 for the $200 part, and then $150 more to 'diagnose' the problem!

Good luck,

Fred.

[Blacklane]

If it starts, that eliminates a lot of issues. I would look for a fuel interruption problem first: shut-off valve closed, bad fuel pump, clogged fuel filter or line, or a clogged air vent.

[gbopp]

Did you change the fuel filter first?

[midnightsadie]

berry,s is ok,I guess, but to eat up gunk use sea foam, wal marts or a parts store, if your handy? take apart and clean, quit turning screws that don,t need turned, it ran at one time just fine on there old setings. and if your fuel tank is at a quarter tank it won,t run either built in safety feature.

[azrving]

You need to isolate the problem. You do have enough fuel in the rig, correct?

It take 3 things for it to run
Compression
Fuel
Ignition

You basically have compression or it wouldn't run at all. You have ignition but you could be losing it. You have some fuel because it tries to run. When it dies out, you need to prove if it's the ignition or fuel. Use a spray bottle with a small amount of gasoline in it to spray the carb throat as it begins to die out.

If it recovers and tries to run then it is in fact not getting fuel. If it dies out anyway, it could be losing ignition. It could lose it's ignition for a number of reasons but a common one may be an issue with the low oil shut down or low oil pressure.

Have a fire extinguisher on hand and a garden hose. I do not know your capabilities but people burn their houses and garages down doing this stuff. Be careful. Just trying to be sure you dont have a disaster.

If it recovers when sprayed with gas you then need to prove why it's not getting steady fuel. It could be a bad fuel line sucking air at times. A restricted filter. Plugged pick up tube.

I know the pump is new but...The pump has to be able to produce pressure but also deliver volume. If its an electric pump and you were to pump fuel into a bottle you would see that it should spurt out at a pretty decent rate and fill a pop bottle in seconds not minutes. If it is erratic look for air leaks in the line. An air leak in the fuel hose can be an aggravating problem that only shows itself at times.

The proper way to address the carb is to remove any jets and thoroughly blow it out with compressed air. The problem is that some carbs and jets can be a real pain. If the bowl was not full of crud or varnish you may not even have a carb problem. if it was trashy in the bowl, sometimes the carb cant be saved. The best carb soaks are with a product called hydro seal made by gunk. It's nasty stinky stuff that I would only use as a last try. It will eat ALL rubber parts so you need to be careful with it.

[Vulcan_Rider]

My Onan dealer in Ocala installed a new carb for me for less than $300.
IF you can get a new one for $200 it probably isn't worth messing with the old one.