Outdoor Power Equipment and Small Engines - Honda Generator EN2500

Hi all,

I've a Honda gen EN2500, the engine will start fine but after approx 20 seconds will shut down -- you can watch the linkage "Carb" move to the shut off position. If I keep starting it approx 7-8 more times while restraining the linkage it will finally stay running and will work fine -- my guess it is getting warmer each time -- It only happens on the first cold start. I thought it might be the "Oil alert system" but I've changed the oil and adjusted the proper oil level -- I'm wondering is there anyway to disable that system long enough to troubleshoot? My guess is, this system has a switch that could be faulty under cold conditions -- Anybody heard of this sort of problem? The gen has only approx 50 hours of use.

Kind regards...

I would say the governor is moving the throttle to open it up and give it more gas to compensate for the decreased rpm (that's how the governor operates). This indicates that it is probably running lean. It needs a richer mixture when the engine is cold. As it warms up, it can run on a leaner mixture...which is why it is running after several attempts. Problem is, if it's running too lean, it is damaging the engine. I suggest cleaning the carburetor.

run it on half choke for a minute untill it warms up. i have a log splitter and an air compressor with honda engines on them and they both act the same. if you find the unit will only run with the choke in any position other than fully open after it's warmed up you have a problem.

I tried your idea but was unable to get it started at half choke... I'm going to take the carb off and try cleaning it, although I've never left old gas in it and have used fuel stabilizer...

Thanks for the suggestion...

Yes, makes sense -- I'm going to clean the Carb and try it again...

At first glance the carb seems pretty simplistic, Keikhin is wrote on it -- could it be a matter of a richer adjustment? The two adjustments on the carb are witnessed mark from the factory and haven't changed...

Kind regards...


Thanks for your help...

I tried your idea but was unable to get it started at half choke... I'm going to take the carb off and try cleaning it, although I've never left old gas in it and have used fuel stabilizer...

Thanks for the suggestion...

not suggesting you start on half choke, once it's running then go to half choke untill it warms up. should only take around thirty seconds or so of run time before it's good to go with the choke off.

Finished cleaning the Carb -- wasn't dirty but gave it a good soak in "Gunk" and blew out with compressed air , removed jet and cleaned all looks good.Re-assembled and started perfect as usual, then shuts down after 20 seconds -- nothing has change at this point...

Regards...

Sorry, that's what I meant -- it starts ok then I put it to half choke -- still shuts down after approx 20 seconds... I now have the Carb cleaned and same thing is happening...

Check the flow of fuel from the inlet needle to the bowl. It sounds like the bowl isn't filling up fast enough to keep up with consumption. Try loosening the gas cap just in case, but I think it would take longer than 20 seconds for a vacuum to develop in the tank bad enough to kill the engine.

Once I get it past the shutdown after 20 seconds period -- after about 7-8 starts -- and it's up and running on its own, it runs perfect and then you can shut it down and restart it first pull.
I'm still wondering about the "oil alert system" I wish I had a better understanding of it -- I guess it's a switch that if it senses low oil press it kills spark? Maybe when the engine is cold, pressure to the switch is restricted and as it warms/viscosity allows switch to see the correct value hence, pressure is allowed to build up.
I might be grabbing at straws as I'm prone to always go the non-KISS method(Keep it simple stupid"...

what viscosity oil are you running? to high viscosity will definitly cause the problem you are talking about. i have experienced it with our generators. use a good synthetic multiviscosity oil and don't allow it to get dirty.

life begins when the kids leave home and the dog dies.

I used Honda oil that was originally put in it -- I've never deviated from that...

Check fuel filter for blockage. To check, disconnect fuel line from tank, unscrew filter, and clean as needed. Check fuel pump for dirt or foreign material.

Has spark plug been replaced? A defective plug can cause some crazy and misleading problems. NGK spark plug BPR6ES gapped 0.028 to 0.031 inch.

Test for spark immediately after shutdown. If no spark, problem could be in Oil Alert System or coil. The best way to test for spark is with a spark tester.

I keep forgetting that it runs normally after the 20 seconds. I'd still say it is running a bit lean. I've opened the main jet a tiny bit on one or two hondas to help with the situation.

[QUOTE=Newfie1;1495297]I'm still wondering about the "oil alert system" I wish I had a better understanding of it -- I guess it's a switch that if it senses low oil press it kills spark? /QUOTE]


oil alert is a float switch. only senses oil level not pressure as there is no oil pump in the engine. try disconnecting the wire from the float switch. it's at the base of the crankcase and looks like the end of a bolt with a wire coming out of it. just as easy to disconnect at the on/off switch if it's the one mounted on the flywheel cover. sometimes those systems act up and if that's it i doubt i would replace it if it were mine.

Took plug out and cleaned it -- condition of plug wasn't showing signs of running rick nor lean -- plug looked ok but I cleaned it up and re-installed... Again, once it gets through the start process, it runs excelent...

I didn't notice a fuel filter -- manual doesn't speak of one -- unless it is inside the bottom of the plastic fuel tank? I assumed Honda was using the fine mesh gas fill filter that this gen has to prevent any contamination into the system during filling -- the fill screen/filter is so fine it's hard to put gas in the tank without overspills... It runs great once your of the long start process...

Defective spark plugs are extremely common. Most manufacturers recommend spark plugs be replaced at set intervals and spark plug replacement is part of the tune-up process as spelled out by most manufacturers.

Spark plug cleaning is outdated. No one can look at a spark plug and verify its condition.

When I troubleshoot a no start or hard to start engine I install a new spark plug after I check for spark, check compression and place a shot of fuel in the cylinder prior to attempting to start. I charge a minimum shop rate and have made a many of a dollar simply because of defective spark plugs.


Good luck,
Airman

For what it takes I'll give it a shot -- thanks for your advice...