16kw lp gas generac generator not starting

Generac, Guardian, Honeywell, Siemens, Centurion, Watchdog, Bryant, & Carrier Air Cooled Home Standby generator troubleshooting and repair questions
Post Reply
Fast eddie
New Member
New Member
Posts: 4
Joined: Mon Jul 29, 2019 9:57 am

Mon Jul 29, 2019 11:02 am

Morning all, my generac 16kw air cooled generator not starting. It's a 16kw lp gas 990 engine stby generator , 1in pipe 7ft length. Model #0058240, S/N 4428528. My problem is the engine won't start, battery fully charged, when I attempt a start it would only start if I squirt some quick start in the mixing box or using a Allen wrench and inserting in one of holes in the cover on the fuel regulator which depresses the lever behind the diaphragm. The generac tech advised me to replace the regulator. I replaced it but the engine did the same thing. I checked the fuel pressure which was 11.5 in/H2O, compression test was 210psi on both cylinders, no fuel leaks. When running it would run with load and auto shutdown without a problem. I seems as if it's not getting the fuel for starting, is there any thing else I could check.
I live in the Bahamas, 80 deg all year. Unit is serviced twice a year.
Chris
Site Admin
Site Admin
Posts: 601
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

Mon Jul 29, 2019 3:18 pm

When was the last valve adjustment and what type of spark plugs are installed?
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
Fast eddie
New Member
New Member
Posts: 4
Joined: Mon Jul 29, 2019 9:57 am

Tue Jul 30, 2019 12:31 pm

The valves were adjusted in March 2019, and plug type NGK. BCPR5ES11.
Chris
Site Admin
Site Admin
Posts: 601
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

Tue Jul 30, 2019 8:59 pm

I'm not up on my plug cross references but these units can be picky about plugs... The correct plug is a Champion RC14YC4.

Regarding the valves, are you sure they were properly adjusted and at TDC?

The next thing I'd check is to make sure the choke plate isn't bent up allowing extra air into the rear intake port. It should sit flat against the plastic mixer body.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
Fast eddie
New Member
New Member
Posts: 4
Joined: Mon Jul 29, 2019 9:57 am

Wed Jul 31, 2019 1:41 pm

The plugs are the correct cross reference, regarding the valves, they are set to .003", the choke plate is not bent and slides smoothly over the intake ports. I don't have a problem when the engine is running, my problem is getting fuel from the regulator to the mixer box to get it started. Does the engine create a vacuum when cranking to assist the diaphragm in the regulator to overcome the spring tension on the lever to open the port to allow lp fuel to get from the regulator to the mixing box.
murphy
New Member
New Member
Posts: 24
Joined: Thu Nov 15, 2018 4:19 pm

Wed Jul 31, 2019 2:47 pm

Yes, it is called a demand regulator. Fuel should only flow when the engine demands it via a vacuum. If the unit has not run recently there will be no fuel between the regulator and the carb. It has to crank long enough to fill the line with fuel.
Chris
Site Admin
Site Admin
Posts: 601
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

Wed Jul 31, 2019 3:20 pm

Yes, that's exactly how it works. I mentioned the valves because if they are too tight, the lack of vacuum can produce the results you're describing. The compression being 210 would make me think otherwise, but had to ask...

Along the same vein as Murphy, if the unit has sat for multiple weeks, these models (for whatever reason) need to be choked manually when cranking to get the regulator moving again. Sticking a gloved hand over the other intake port while it's cranking usually does the trick. If it's an ongoing issue each week, it could be a bad regulator, or even that the fuel pin has shifted slightly causing a strange fuel mix.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
Fast eddie
New Member
New Member
Posts: 4
Joined: Mon Jul 29, 2019 9:57 am

Wed Aug 07, 2019 5:02 pm

Hi Chris, looks like I got it fixed. I took of the mixer box, replaced the sleeves and gaskets on the intake manifold, used a little high temperature sealant, put back together and it started without fuel assistance.
Thanks for your assistance.
Chris
Site Admin
Site Admin
Posts: 601
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

Wed Aug 07, 2019 7:20 pm

That's great news! I'm glad you got it figured out and especially glad you let us know!
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
Post Reply