16kw running rough

[banshee]

I recently purchased a new 16kw generac and its does not seem to start and run correctly. I posted a thread before about long crank times and throught maybe this is normal. After listening to the generator for a couple exercises and manually starting genset it just seems it should be smoother and start quicker. Has anybody had issues with hard starting and rough running. The rough running I am comparing to my twin kohler engine in my zeroturn mower and would think propane should be the same or smoother and that is not the case. The generator is set for propane and is connected to a 500 gallon tank. The propane company measured the w.c. 11" stopped and 10" running.This W.C. was measured at the regulator before entering the generator. I am wondering if I have a carburetor problem or a generator internal regulator problem. Please let me know if anyone has had an issue like this or what I can do to troubleshoot this one.

[Kelly Myers]

What leads you to believe its running rough? Is it shaking? Is the governor hunting?

[banshee]

It is not hunting or shaking it just sounds like it has a flutter. The flutter sounds worse when running on exercise at lower RPM and unit shakes a little more on exercise then normal.

[tdsa]

My 16 KW is running rough using LNG. The service tech replaced one spark plug and it smoothed up. However, last week when the power was off, I noticed it running rough again. Also, the incandescent lights are flickering. I changed both plugs (gapped at 0.040") and it is still running rough. When I open the air cleaner and close the choke cam approximately 30% it smooths out. Anybody have any suggestions???

[JimO]

Mine smoothed out when I took the plug gap down to .020. Easy experiment!

[Dave Carney]

Check your valve lash, even though it's new. Mine was off. Had no gap at all on one cylinder so the valves were not closing all the way.

[nextwave]

We have come across a few of the 16's running rough in the last couple months. Oddly enough they were Centurions - all of approx the same age. We were not the installing contractor...did valve adjusts on both, checked plugs, gas pressure perfect. One failed a comp. test miserable...getting a new engine. The other is still in being tested and tweaked. Anyone else with similar issues?

[Kelly Myers]

We have come across a few of the 16's running rough in the last couple months. Oddly enough they were Centurions - all of approx the same age. We were not the installing contractor...did valve adjusts on both, checked plugs, gas pressure perfect. One failed a comp. test miserable...getting a new engine. The other is still in being tested and tweaked. Anyone else with similar issues?

I'm guessing you're a service dealer. Did you notify Generac of the serial numbers?

[JimO]

Yes. I have a 13K and a co-worker has 16K (same engine), bought the same time, same store. As I have indicated in previous posts...mine ran perfectly all year as did his. Mine is right outside my shop and last fall I started to experience backfiring and roughness on startup at the weekly excercise. I did all the checks...LP pressure, valve adj., ect... I finally found that regapping plugs to .020 gave me reliable starting with no backfiring. More on mine in a new thread...

3 weeks ago, my co-worker came in my office as wife was on the phone, to say the power was out at home and gen was running but backfiring continuously. the next day, he reported that it had smoothed out and ran for about 12 hours but...Upon inpection...he found the plastic Air Filter cover had a 2" hole melted in it and the insulation on the lid charred. I went over to inspect, checked the LP pressure and figured it had to have ingested enough plastic and debris to require more cleaning and disassembly. Time for a Warranty Service call. The local tech came out and ran it, it oversped, started knocking and destroyed itself. He has a new engine being installed tomorrow.

Generac needs to get to the bottom of these issues of units running rough and backfiring ect...My warranty is up in June so mine will probably blow in July!