Genset runs about ten minutes and shuts down. when you start it runs fine for ten minutes. cleaned carb checked fuel pump, drained tank put new gas. runs ten minutes and quits

SIMPLE Onan Generator Fuel Pump Test and Replacement Tips

check for a faulty sump oil switch . check for faulty coil ( magneto on the flywheel) as the time it runs suggests that it is breaking down internally.

Definatley a fuel / carb problem . remove carb-remove fuel bowel turn carb upside down float should be level to carb body if not replace needle and seat. drain fuel from tank into a clear container to see if there is water in fuel (water will settle to bottom of container ) also check jet in middle of carb to see if plugged.

Replace fuel filter after cleaning tank thouroughly, to clean tank remove fuel line at carb. Drain all fuel then leave line loose until you flush tank with carb. Cleaner then blow out tank with compressed air. Now install new fuel filter and check your fuel can for trash and water better yet just add fresh fuel.

Your carbs are dirty and need to be cleaned. A tank of bad gas or old gas can gel up the jets. You buy gas, drive home, and when you get there the bike stops idling. Light gelling can be fixed by draining the carbs (screw on bottom of bowl), pulling the fuel line off the tank, and squirting some motorcycle carburetor cleaner down the fuel line. Plug the fuel line back in turn on the gas and start up the bike. If that doesn't work, using the same procedure buy some Chevron Techron fuels system cleaner, pour directly into the carbs and let sit over night (also drain tank and heavily treat one gallon of gas and put in tank) Fire up bike and let run ,idle, slow drive for 5 to ten minutes. This will usually get cycle idling without disassembling carbs. If it still wont idle you will have to take off the carbs, disassemble and clean blowing through the jets and jet passageways.

unleaded fuel is notorious for going stale,and it can leave a resinous coating in the carb-try running the saw on half choke with new gas and less oil eg 50 to 1 for say ten minutes,this should clear the gunk out-if this does not work,you have two choices-strip and clean the carb,or adjust the H (high) scew on the carb anti-clockwise by a quarter turn a time till it revs out full bore-good idea to remove the chain and wear ear defenders when adjusting-and always use a chainsaw at its max rpm,or you run the risk of "kickback"

Lets start with the basics. Is the gas valve turned on? Do you have plenty of gas in the tank. If not, turn the gas valve to the "reserve" position if your valve has a reserve setting. There may be a water trap bowl at the base of the gas valve. Turn the valve off and remove the bowl if you have one and then clean and replace it.

Next, drain the carburetor. There should be a screw on the lower side of the carb float bowl. Remove the screw then replace it after the fuel drains. Turn the gas back on and wait a minute for the carb to fill with gas. Install a new stock NGK spark plug and try to start the engine.
If the bike doesn't start after a couple of minutes then shut off the gas and remove the carburetor.

Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray all the little airways and fittings in the carb. Remove the two screws on the outside of the carb and spray into the screw holes as well.

Be sure to put each screw back in the hole it came out of. IMPORTANT > do not tighten these two screws down. Only screw these in until they LIGHTLY seat. Now turn each screw one and one half turns outward. Put the rest of the carb back together, clean the air filter and install the carb. Let the float bowl fill then start the engine. This process should get you back on the road.

Pleas rate this as " FixYa " if my solution works. Thanks

a couple things... i presume you have already put it back together. but dirt in the fuel line will not allow fuel thru and that appears to be the problem.... the float controls a tiny valve... the theory is the float shuts off the fuel supply to avoid fuel spillage.

ensure there is proper movement of the float up and down.

if that appears fine... attempt to start it a few times.... afterward pull the spark plug... is it wet (fuel) ?

Robert

If the oil is dirty, it will not pump properly. I recently had this problem, once I changed the oil it was good to go.

My answer:

Not knowing your exact model # or how old it is, and knowing only what you said above - TOTAL RUN HOURS unknown as well? - I can only give you several possibilities of what the problem might be - even though I don't know the exact model # and which engine you have on the Genset. Porter Cable as well as Coleman and others do not themselves mfr much of anything today, but like with many USA companies out there today it does private label out to a lot of mfg vendors (mostly in China btw), and the Genset gas engines are numerous. From Briggs & Stratton to Honda to Subaru and so forth...

I also don't know what normal LOAD you were putting on your Genset there, or have been putting on it previously, or at what RPM you are normally running the engine at - as to half throttle or full throttle setting?? I take it that it's a Briggs & Stratton 4-stroke single cyl, or is it a Honda 4-stroke single/twin cyl engine?

Any Genset that is going to be put into storage for that long a period of time I would first and foremost recommend running the Carb Bowl dry first by running the Genset at FULL speed, and while running turning off the gas until it dies. Thus removing as much gas from the Carb Float Bowl as possible!

Most people do not do this and forget about that small amount of stale gas in the Float Bowl, and that is what causes VARNISH in the Carb Bowl faster then anything else.

Just putting a gas preservative in the gas tank doesn't solve the VARNISH problem because that never gets down to the Carb to begin with if the gas line shut-off valve is closed before the preservative gets down there.

If the Float decides to stick while in storage, and then it's brought out to fire up naturally the gas will flood out the Carb and probably the Air Filter Box as well.

It's always better to store the Genset DRY! I know I do and I have NO problems at all with stale gas, etc.

Since all Gensets need to be run a minimum of 10 minutes every 30 days (every 1 month religiously), or whatever your owners manual recommends - if you haven't been doing this, or don't run the gas out of the Float Bowl before shutting the Genset down after each use - then most likely the Carb is gummy or possibly has dirty gas in the bowl and is the problem.

I seriously doubt you did any damage to the engine by the recent gas over-run and flooding.

You might try and tap carefully on the bottom or side of the Float Bowl with a hard rubber hammer first to try and see if you can dislodge the stuck Float inside. If there is a WIRE at the bottom of the Float Bowl on your model - DO NOT HIT THAT GAS SHUT-OFF SOLENOID WITH THE RUBBER HAMMER - as you will do damage to it! If this dislodges the stuck Float then your problem is solved!

You may still want to run a bottle of Carb Cleaner in the tank just in case to clean out any residual buildup in the Float Bowl, etc. If it runs fine then No Problem.

First and foremost always check your OIL LEVEL and make sure you have changed it out according to your owners manual!!!

If your Genset still runs sporadically for only a short time and then starts to cut out I would look more for like a fuel vapor lock (partially closed or clogged gas cap vent), a possible dirty fuel filter, possible water moisture in the gas tank or in the Carb bowl, possibly dirty Carb in general along with it's dirty Float Bowl, Float Pin, Float and Needle Valve, and any Adjustment Screws that go Into the Carb Body.

It's hard to say unless the Carb first is broken down, checked for proper Float action setting, and/or cleaned out accordingly if dirt is indeed present in the bottom of the Float Bowl.

If all looks good there Carb Bowl wise then you will next need to check the FLOAT adjustment itself to make sure you aren't flooding the Bowl. Your Operators/Service Manual should have that adjustment there. If not let me know and I'll post it for you. Also the air/fuel mixture Jet Adjustment Screws will need to checked as well.

Let me know if you should need that adjustment procedure as well after you first check out everything else I stated above?

That covers everything from a fuel standpoint.

Again - You do know that all Gensets should be started and run for at least 10 mins every 30 days - right? If you didn't know this - now you do! Every good operators manual should state this.

It just doesn't sound like it's starving for gas - that's for sure!

The gas tank fuel line does have an in-line fuel filter correct? If it doesn't you definitely need to add one for dirt protection!!

Having covered everything from an fuel standpoint engine wise - there is only one other thing left Genset wise.

Beings your Genset there might just have some high RUNTIME HOURS on it - it just could very possibly be what sounds like to me (and I personally HAVE SEEN this happen myself firsthand) that the generator brushes are nearly shot - as in almost worn out. They may be getting too too hot - as from excessive current draw at point of contact, and thus the generator sensing circuitry itself is doing an electrical CUTOUT!!

An added protective Genset circuit feature in that the generator itself may indeed be linked to the engine as a type of REV LIMITER or CUTOUT on the Maintenance-free Magnetron® electronic ignition. Again - your operators or service manual should have a pretty good troubleshooting section in it unless you don't have that anymore or never got one if you bought it used to begin with.

If you unscrew & remove the Generator brushes, and they are indeed below the recommended length (or worse case they are indeed totally worn down) then that too most likely could be your problem right there.

If you choose to replace the old brushes with new ones yourself - be very careful when seating the new ones - as to their insertion and cap retainer tightening. Never over-tighten those black plastic-like brush retainer screw caps - for if you break one (hard to get immediate replacements is why), or fracture one it could cause the Genset to fail under LOAD, and that very well could do some severe damage to the generator part itself. Take your time doing it, and be patient!!

It has to be one of the scenarios listed above, as I've covered every possible cause short of a broken wire somewhere - which in that case you will have to schematic trace and Ohm out wire to wire contacts. This being the least likely scenario from experience.

If you indeed find the Float Bowl assy to be the cause of dirt contamination or varnish build-up clogging the Carb, and you need a walk-through of taking it apart, cleaning it out, and then re-assembling it again - as well as re-adjusting the fuel mixture Adjustment Screws - just give me a shout here, and I'll walk you through it step by step.

Please post me a reply as to the found problem there, and the resolve to it by following my recommendations above. Also please rate my troubleshooting fix as well.

Keep me posted and I'll follow up as well.

Best regards,

Frank

PS:

GENERATOR OIL CHANGE NEGLECT

People experiencing starting issues often are not using fuel stabilizer or not changing their oil. I myself or any good repair shop will first pull the oil out, and most times we'll will find that it has metallic build up common from any small gas engine that has been neglected.