I have an em3500 honda generator which starts stalling out after 1/2 hour to an hour like it is running out of gas and then shuts off. I can restart it and it will run for 1/2 hour to hour and do the same thing. Lots of gas and carb is clean. Ignition coil?

it is not any kind of car or truck,so moved you to portable elect gas generators.
does it burn gas/petrol or LPG?
with engine stalled, oil lamp on is 100% normal
but never at the time of stall (or just before)
the oil pump runs off the crankshaft is why.
new spark plug is cure. i bet.
or use chock longer.
carb, gasoline , petrol.
if spark tip is in raw fuel , turn off chock and crank it dry.
the gen has many buttons switches make sure all are set correct for sure on./off .
is it elect starter or hand cord cranked or both?

Make sure that the spark arrester screen on the exhaust isn't plugged with carbon. It takes just thirty seconds to pull it out. If it is clean, then the fuel filters are the next step. Hope that helps. Rod

find a honda dealer and pray its not expensive... Or find a small engine shop and see if they have some junk generators laying around and buy the best tank they have and make it work...

Maybe your gas cap is bad an not ventin allowing air behin the fuel

The B&S unit uses an AGM battery. You can get one at Interstate. Use the 35 amp-hr size for this unit.

Honda makes quite good gasoline motors. I doubt it is a valve timing issue but it might be a burned valve or a valve adjustment issue. What does after a while mean? A couple of minutes or 4 hours? Is it running for just a short while and then stops or it runs well for a long time and then stops?

With regrets, I do not have any personal experience with generator troubleshooting. However, I have been informed by some people that have good experience with them that a generator needs to be run for a couple of hours every month to keep the system in proper order. Should a generator sit idle for ten months, the fuel can actually "shellac" inside the carburetor and lines. This will then travel to areas that will gum up - thus the necessity to drain the tank and carburetor completely.
Here is their advice:
http://powerequipment.honda.ca/parts-service/storage-tips
Your service person(s) may not be aware of the time the unit sits idle, and if they are aware - then they are not giving you straight facts (in my opinion). I would suggest contacting Honda customer service directly, and explain this situation to them - they will probably be more then happy to have a technician assist you properly. Contact the 'customer relations' number, and they will direct you from there. Here is the link:
http://honda.ca/contact_us

I am sorry I couldn't be of more help.

Gas or Spark Plug!

The issue with the generator that gets low and high when it start running out of gas that effect the A/C and result of high voltage getting to the unit and burn the capacitors and it should by saved by the fuse make sure that the gen not run out of gas if you have the A/C on and that the fuse is the correct one for the A/C and again check the air and see you may got a bad capacitor.
....let me know if that work for you and please do not forget to rate my service so I am able to continue providing same...god bless
1 thump not related
2 thump related but no recommendation
3 thumps related worked some issues
4 thumps related worked all issues and satisfied

Oil pressure switch. Check it and make sure oil level is correct. The oil switch will cause this

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