bucdup
Thank you in advance for your help. I have a Generac 18kW air cooled generator at a house I am renting out. The tenant noticed a gas smell while doing some work outside and notified me. I sent out the gas company to test for leaks and they told me the leak was inside the generator.

I went out to test and you could smell gas. I started going through the system and found a strong gas smell when I would take off the cover for the air cleaner. My initial thought was the fuel solenoid was not closing properly allowing gas to continue to leak into and through the system. I replaced the fuel solenoid and tested that it was working properly.

Still, when I will run the generator there is a strong gas smell afterward emitting from the air cleaner. I assume since the fuel solenoid is closed that the gas leaking is the gas inside the system, but I do not see where and how this can be happening.

Any suggestions?
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bronco
maybe the regulator has a crack in it allowing gas to get by the soleniod.
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douglas123
might want to check your fuel presure in. If you are using a 2lb system with a reducing pressure regulator it might be set too high not allowing the solenoid to fully close. Make sure you are not over 14" of water column.
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ohmslaw
I would pull the fuel solenoid and check for a sticker on the plunger. If the sticker is there I would replace the plunger but you may be able to remove the sticker and get it to stop leaking. Inspector #5 strikes again. This sticker will produce a gas smell in the air box .


Tim
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douglas123
Awesome observation. I wonder what inspector #5 gets paid by the hour. That's right up there with the barcode sticker on a pvc fitting where you glue the joint together.
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ohmslaw
That was not the first time I found a sticker. I found this on 2 units.
Tim
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bucdup
There is no sticker, but I am meeting the gas company on the job to verify the gas pressure. I did not think of this as being as issue as far as the solenoid staying open, but it does make sense. I replaced the solenoid already and tested the operation. Thanks for your help.
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douglas123
I have been studying on the situation. Got to thinking the regulator works on a vacum draw. Have you thought of checking that the spark plugs are producing a good blue spark? Might need to check valve adjustments also. Could be that unit is running rich and plugs not firing hot enough. Just a thought.
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ohmslaw
Douglas,
The unit leaks in the off position. there should be no gas past the solenoid.
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douglas123
ohmslaw,
Curious to find the outcome of this scenario. I was talking with some of my other generac tech friends. Having not seen the unit I was thinking a little outside the box so to speak. Have seen some strange things over the years but by no means have seen it all. I like these type of problems. Currently working on a unit that is six years old,has never worked properly and the customer has had many different folks come out and attempt a successful repair. I have resolved all of the customers issues except one. I talked with the factory about my own modification of the field flash circuit on this particular unit. Being the unit is NOT under warranty it would be an acceptable repair as far as the factory was concerned. Is there any way to get more folks to posts pictures of what they are working on. Pictures in my book are a valuable resource in getting to the root of a scenario.
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bucdup
Sorry I took so long to update but I wanted to let everyone know the results. douglas123 was correct on this one. When I started to think about it I remembered there was no secondary regulator on the NG line to the unit and we could quite possibly have too high of a gas pressure. The gas company came out and found 13"WC NG pressure at the unit. They adjusted the pressure and sure enough, solved the problem. The pressure was causing NG to blow by the solenoid when closed. They are installing a secondary regulator now to permanently fix the problem. Thanks for your help!
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ohmslaw
Curious... the units are capable of taking 14"wc LP so why would 13"NG be a problem? I currently supply a new 22kW with 14" NG and it does not leak.
Could be a faulty plunger that shows up at the higher pressure.
Tim
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