Problems with 20kw gen-set

[coobie]

A friend of mine in the commercial generator business would say, the problem is that it is a Generac!
Has nothing good to say about them.

How many RPM does the unit run at, just out of curiosity?

I actually installed one (on Propane) at the request of a customer. My feeling, and hearing the thing run at 3600rpm is that it won't last long! Maybe the regular excercise has already worn it out.

To funny,got love folks who brand bash instead of trying to help.I have a generac 17kw that has been flawless the last 5 years.To the orginal poster have you adjusted the valves yet?

 

[Larry Caldwell]

Battery is good and so is trickle charger. It cranks over ok, it just acted like it's being starved for fuel. The first time this happened ( 2 wk ago) it would rev up & die. Done that a couple times before it caught and stayed running.

This time it popped a couple times and backfired through muffler. Went outside and hit manual start and I'll bet it didn't turn two revolutions and away it went. Perplexing!

If it sounds starved for fuel, it's probably starved for fuel. I bet the auto-start is not popping the solenoid, but the manual start did fine. The generator is probably just fine, but the control systems have a dirty connection or something. When the weather warms up, take all the connections apart, buff them with fine emery cloth and put a light coat of anti-oxidant on the parts before reassembly.

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[buickanddeere]

Many generator failures can be traced back to an undersized or borderline sized unit being maxed out in hot weather

 

[Western]

We had nearly the same Genstet you have, bought from Graingers for an Ostrich farm in 1991. Generac 20k also.. We had something similar to what the OP describes, happen the first winter. It was under warranty and the service guy ended up replacing a Solenoid, as others here have said. It has been so long, I dont remember any more than that, but I do remember the repairman said cold weather can make a weak solenoid worse. Don't know if that is true, but it ran without hick-up for 11 years after that with yearly maintenance.

 

[Gary Fowler]

I just bought a portable Generac brand XT8000E from Lowes and the salesman said of all the generators they sold (Briggs and Stratton, Generac, Stanley and Troybuilt,) non of the Generacs have ever been returned because of a defect while they get many returns on the other brands.
I haven't started mine up yet so no more comparison between any of them other than reviews from users of all brands that I looked at before buying which run from great to P.O.S. on mostly all brands except Stanley which not one good comment was posted about them or their service dept.
As stated by Grsthegreat, many folks never service anything and expect it to run forever and then give a bad review when they crap out so you have to put those in prospective. Of course an industrial installer is going to bash anything less than his bread and butter stuff.

As for the OP, I must have read something wrong as I thought you stated the Generac guy came out and checked it out but it sounds like he didn't start it (weird) as the OP stated he will have to wait till next auto start sequence to see if it worked. As for spark plugs, they can go bad from just setting especially NG brand. I had an issue with them on my boat (worked and then misfired off and on) and mechanic instantly said to change the plugs when I described the symptoms. They had 30 hours on the engine, but 3 years of use. Sometimes they worked, sometimes all they would do is misfire just like starving for gas for a bit then kick in and run normally.
I would change the plugs if it were mine regardless of hours on the engine.

 

[Toyboy]

you generac naysayers drive me nuts. Ive been installing generators for nearly 30 years. Big commercial units and smaller residental units. Ive installed Honeywell, Generac, Siemens, you name it.

Funny thing is, alot of other manufacturers use Generac manufactured engines and parts. Generac is the WORLDS largest generator manufacturer.

Ive never ,... never... have had a call that a unit failed due to generator manufactured issues. they have always been from misuse or neglect. I just fix two units that wornt working after a power failure. The owner NEVER changed oil or checked batteries since they were installed. They were installed 7 years ago. After servicing them, they both fired right up.

Nothing will last if its not maintained, and most people forget their generators.

Now for the OP's issues. I have run into similar issues in the past. I assume that this is an air cooled unit, so ill not worry about heaters (extreme cold kits). Things to check

1. check that gas/fuel solenoid is opening. That needs to be looked at
2. Spark plug foul and check gap still have original plugs w/less than 30hr on them
3. Fuel pressure set wrong it was set at 7" and has been reduced to 6"
4. The manual talks about checking #14 wire on the control harness to make sure its connected, but this is quite a chore to do. I'll bring that up w/installer
5. A week battery will cause a weak spark on the sparkplug. You can do a spark plug test like you do with a car to check spark. Battery sems fine to installer trickle charger too

just for your info, ive also fixed a unit where the installer used pipe dope not rated for NG on his generator install, and a large clump of it broke free and obscured gas flow. Found that after unhooking the fuel lines. This made the generator act erratic....rev and stall, hard starts.

gas company did he piping

 

[Toyboy]

I just bought a portable Generac brand XT8000E from Lowes and the salesman said of all the generators they sold (Briggs and Stratton, Generac, Stanley and Troybuilt,) non of the Generacs have ever been returned because of a defect while they get many returns on the other brands.
I haven't started mine up yet so no more comparison between any of them other than reviews from users of all brands that I looked at before buying which run from great to P.O.S. on mostly all brands except Stanley which not one good comment was posted about them or their service dept.
As stated by Grsthegreat, many folks never service anything and expect it to run forever and then give a bad review when they crap out so you have to put those in prospective. Of course an industrial installer is going to bash anything less than his bread and butter stuff.

As for the OP, I must have read something wrong as I thought you stated the Generac guy came out and checked it out but it sounds like he didn't start it (weird) as the OP stated he will have to wait till next auto start sequence to see if it worked. As for spark plugs, they can go bad from just setting especially NG brand. I had an issue with them on my boat (worked and then misfired off and on) and mechanic instantly said to change the plugs when I described the symptoms. They had 30 hours on the engine, but 3 years of use. Sometimes they worked, sometimes all they would do is misfire just like starving for gas for a bit then kick in and run normally.
I would change the plugs if it were mine regardless of hours on the engine.

My installer was out the first time this happened and it fired up on manual for him but acted like it was starving for fuel a couple times. This occurrence he did not come out because his end (electrical) was doing it's thing and he advised me to get the gas pressure checked which I did.

My installer originally set the machine and did all the electrical but had gas co. do piping. So I can see his point that if its cranking as it should, but not starting, it sounds like a fuel issue and I agreed w/him.

Now this unit has been installed for 2 years and this is the first issue we've had. I'm starting to lean towards plugs and fuel solenoid as next step. Once the control board gets a an RPM signal it energizes the fuel solenoid. Weak signal? sticking?

I have ordered up a cold weather kit to be installed in the next week. Will it make a difference? Hope so.
By the way, Kurt (installer) has over 25 units in area and I'm the only one on NG and the only one having an issue. All others are propane.

 

[charlz]

If it requires sensing the correct RPM to open the fuel valve how does it pick up the RPM? Is there a replaceable sensor? Could be a bad RPM sensor and it won't start because it doesn't see any or the correct RPM's. When running bad output from the sensor may cause the fuel valve to momentarily shut which gives the starving for fuel symptons.

 

[hr3]

Pull the air cleaner and check the butterfly choke make sure it closes on start and opens on run,,, If that is working properly you have a fuel delivery issue ,, regulator's hate the cold "We had 5 call outs for this last week".. The other thing would be the fuel solenoid sticking.. A quick way to see is to tap it while the generator is running and see if it changes tune..

Just for giggles also check and make sure when it was installed it was set for NG and not Prop.. I warm weather with no load it might not show up but now that it is cold it might,,,

 

[charlz]

Different generator and different size but sounds like similar symptoms.

Winco natural gas generator runs rough at start up - SmokStak