Generac LP generator didn't start up when needed today

CalG · Oct 17, 2019

Helping a neighbor woman.

We had a bit of breeze blow through, with power out for about 7 hours. She depends on her Generac 15kw LP gas unit to self start.

It didn't today. She called me tonight for help and advice. The unit shuts down with "excessive cranking" fault.

I'm going over tomorrow to put in spark plugs, adjust the valve lash and check the air cleaner condition.

The unit is about 8 years old , doesn't see a lot of use, gets an annual oil change, with a new battery this time last year. It is set for the weekly auto run exercise, but I don't know how it has been functioning in that regard. It needs a hobbs run time meter ;-)

I'm not much for LP gas IC engine subtlies, good suggestions welcome.

tia

Industrial Toys · Oct 17, 2019

I heard this alot, about LP units not starting, but mostly in the cold. But some EXPERTS on here say this is not the case. What were the temps?

You can't mistake one of those things running. She didn't hear it excercise?

PEJ5 · Oct 17, 2019

Good neighbor: You call that a breeze?

10s of thousands lost power in New England and the Maritime provinces. I do not have propane fuel experience, but I think you are on the right track...air cooled engines need spark-air-fuel. In addition to those maybe confirm the choke is not stuck on - yes, I know that is part of air but I am not sure how auto-start engines handle that.

CalG · Oct 17, 2019

PEJ5 said:
Good neighbor: You call that a breeze? 10s of thousands lost power in New England and the Maritime provinces. I do not have propane fuel experience, but I think you are on the right track...air cooled engines need spark-air-fuel. In addition to those maybe confirm the choke is not stuck on - yes, I know that is part of air but I am not sure how auto-start engines handle that.

Is there a choke on LP fueled systems?

radios1 · Oct 17, 2019

CalG said:
Is there a choke on LP fueled systems?

yes!. look here for troubleshooting. Engine Will Not Start On Propane (Basic Troubleshooting) – US CARBURETION SUPPORT CENTER note that the regulator has to be protected from rain, else the vent will freeze and not let the gas flow. make sure the gas is flowing..

CalG · Oct 17, 2019

radios1 said:
yes!. look here for troubleshooting. Engine Will Not Start On Propane (Basic Troubleshooting) – US CARBURETION SUPPORT CENTER note that the regulator has to be protected from rain, else the vent will freeze and not let the gas flow. make sure the gas is flowing..

The unit is in the barn. Under a good roof. ;-) No rain issues to be concerned with, dry as a bone.

CalG · Oct 17, 2019

radios1 said:
yes!. look here for troubleshooting. Engine Will Not Start On Propane (Basic Troubleshooting) – US CARBURETION SUPPORT CENTER note that the regulator has to be protected from rain, else the vent will freeze and not let the gas flow. make sure the gas is flowing..

That article reads "IF you have a choke". There is no indication of a choke in the Generac set up literature.

ruffdog · Oct 17, 2019

Way back when I worked on medium duty trucks and some were propane. They had a "choke" lever attached to the primer button on the regulator and that helped them start. Do these small engines have a primer button on the regulator?

CalG · Oct 17, 2019

ruffdog said:
Way back when I worked on medium duty trucks and some were propane. They had a "choke" lever attached to the primer button on the regulator and that helped them start. Do these small engines have a primer button on the regulator?

Even if it did have a primer button, the gal is not inclined to go out to the barn and mess with the generator. The side panels would need to be removed to access anything engine related. That takes tools, she doesn't do "tools" ;-) It's supposed to be "auto-magic.

From what I read, overly rich is more an issue with LP gas starting poorly than is fuel deficient. Is that likely?

Industrial Toys · Oct 17, 2019

I would take a spark tester, before I ever touched the plugs. Is this thing a twin cylinder, 1800 Liquid Cooled or 3600 RPM Air Cooled machine. The fact that you said, it's in the barn, may suggest it's not some air cooled screamer.

CalG · Oct 17, 2019

CT 990 engine from the literature. Air cooled V twin from the looks.

15kw back up suggests it's a baseline home style piece of equipment.

I notice these coil replacement kits
https://www.amazon.com/Generac-0K63030SRV-MAGNETO-KIT/dp/B00XRF2TL8

Are "weak coils" a common issue with the GT990 engine?

radios1 · Oct 17, 2019

check for spark, if it's there, it must be fuel. if it was overly rich, you'd smell the propane smell.. this problem is why regular exercises are needed to detect problems, it also prevents some by charging the battery and making the fuel delivery system work..

ruffdog · Oct 17, 2019

Out in the barn also means mice and the damage they do.

Industrial Toys · Oct 17, 2019

Just don't gp blowing up the barn!

CalG · Oct 17, 2019

ruffdog said:
Out in the barn also means mice and the damage they do.

I thought about that too. Mice love airboxes! Hence the air cleaner check mentioned in the original post. ;-)

CalG · Oct 17, 2019

radios1 said:
check for spark, if it's there, it must be fuel. if it was overly rich, you'd smell the propane smell.. this problem is why regular exercises are needed to detect problems, it also prevents some by charging the battery and making the fuel delivery system work..

Battery is maintained off the units built in system. If the power Co. is providing juice, the generator battery is being kept charge.

The regular exercise seems like a great tool, and I've asked the gal to pay attention to when the weekly session is heard. But if she doesn't hear anything, what's to notice? I can't expect her to hang around all afternoon on the day the session is supposed to take place. And I'm not going to run over there once a week to check it for her. I can't imagine the weekly cycle timer being that repeatable. the time likely drifts, and the entire process is done in less than 15 minutes.

Please note, the gal is trying to recover from a cancer, she has cateracts and is getting that surgery, and she lives some distance from me (10 min drive) .

kenmac · Oct 18, 2019

the thing about stand by generators is. they stand by most of the time. So, when they are needed, they tend not to start.
Part of this problem was solved when they started the program for them to turn on and run for a while once a week.
Years ago, I ran a propane powered truck. When it was cold out, I Had to start it on gasoline, get the engine hot, then switch to propane

mike48130 · Oct 18, 2019

I had a 15KW that I never had any issues with unless it was very cold. I built a cold weather kit for it and solved that problem.

It should have a built in battery charger to keep the battery topped off, so make sure the battery is good even tho you said only a year old. I wouldn't waste your time on the valves. Figure you if you are getting spark first. There are solenoids for the gas that can always go bad or get clogged.

I assume you checked the obvious that no one turned off the gas?

grsthegreat · Oct 18, 2019

if that unit is 8 years old like you say, it has 2 stepper motors (chokes) take off the air filter cover and make sure the choke plates move when motor tries to crank over. Usually it first closes fully then opens 1/2 way. it may cycle a few times. . Also, there's a small stepper motor in there

and a spring that moves the choke plate over the venturi when cranking. These little motors have been known to freeze up or rust. Theres a second round stepper motor

on the side of the air intake box that should cycle during starting also.

if both of these are working properly, then its either spark issue ( i use an inline spark tester) or fuel delivery. if all else fails, you can take a blunt object like the back end of a drill bit and push on the fuel bellow inside the fuel regulator down by the battery. there are 4 or 5 holes on face of regulator.

while cranking and not starting if you gently push object into one of these holes and unit fires up, you need to replace regulator.

ive never seen mice problems in any generac unit ive worked on. they have a good metal screening system. Changing the mags is not too difficult, but i have not seen that issue too often. you HAVE to verify spark first. You have not stated whether she has had the valves adjusted in the past. i have brought dead generators back to life many times with a simple valve adjustment.

as for propane starting in severe cold, the only issue i've ever seen with this is in the propane tank itself if allowed to get too low, or a tank thats too small. Ive had some people try and run a generator from a 100 gallon propane tank. ive had several issues with this. i even had one guy try and run his with a bunch if 7 gallon tanks. now these will freeze up. I've had mine running when its 10 below and never had any issues . At that time i had a 500 gal above ground tank. Now i have a 1,000 gal underground tank.