# Honda EU3000is Troubleshoot Summary



## Waypoint (Jan 28, 2014)

Posting this in case somebody down the road encounters this problem...it was a real head-scratcher.

During last Friday's snowstorm and power outage, our EU3000is gave us problems. It would start and initially run fine, choke completely off after startup. Smooth engine running in eco on and off modes. After approx 5 minutes, it would backfire out the exhaust, misfire repeatedly, and die. Suspecting a fuel delivery issue...maybe it's running until the carb bowl empties...I removed and inspected the sediment cup (spotless) and carb bowl (also spotless). Opening the fuel valve resulted in normal fuel flow at the sediment cup inlet, and the carb bowl after reinstalling the sediment bowl. No fuel delivery issue.

I then removed the factory NGK BPR5ES spark plug that had approx 260-300 hours on it, and found the interior ceramic insulator cone had a hairline crack at the end near the metal electrode. New NGK plug gapped at 0.030" installed, and all was well again. The crack must have been opening up as the plug heated and expanded, allowing the spark to arc to the lower side. Old plug gap measured 0.028-29" on the cheap gap gauge, so it wasn't very worn. If it happens again I'll switch to Denso W16EPR-U also specified in the manual.

NOTE: Advance Auto carries these, but not searchable under the BPR5ES part #...use 7734.


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## Waypoint (Jan 28, 2014)

Update: I put ~5 hours of run time on Sunday during a planned outage by the utility, no issues! Very unusual that a spark plug with little wear could fail in this manner.


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