Generac 8kw lp low voltage

[plarouche1]

Hi, thanks you for letting me register to the forum.
I have a generac 8kw 0056100, the voltage between L1 and L2 is 125 volts ac, and it is 68 volts between neutral and line, the voltage between the capacitor winding is 1,5 volts ac, without capacitor present, with capacitor present it is around 125 volts , capacitor test good, good fluke multimeter, but I am not sure if it worth fixing. I bought it use, the seller had it connected to 5psi propane, guess what happened, he blow out the mixing box. I had it repair and run the generator the 1/2 psi. motor run good
power is low thanks for the advise. ( ps the generator is alone, no transfer box) the seller didn't have it.

Thanks in advance for your input

 

[Birken Vogt]

I have not had to fix any capacitor regulated models other than to replace a bad capacitor which you have already checked. But if you go to an air conditioning supply house and buy another capacitor that is close, for instance if yours is 58 uF and theirs is 60 uF, they are very cheap, easy to try a new one and see if it makes any difference anyway.

Besides that, there ought to be diodes on the generator rotor, a lot of work to take off the end of the enclosure but a failed diode might cause this problem.

 

[pegasuspinto]

#1 is check the speed of the gen. needs to be close to 60hz output and I am sure that is a 3600 RPM unit (RPM rating will be on the label). So either check the output frequency or RPM, depending on what equipment you have.

Does the unit have an idle feature? Turn it off, or try putting a small load on the unit (light or heater should be safe). I'm not sure if your unit has the idle function however.

 

[plarouche1]

Few more test, capacitor ok, check rpm, low 3100 rpm, when increasing the rpm motor not turning right, open valve area, exhaust spring very soft, part discontinued, I didn't like Generac 20 years ago, personnaly I will say away from Generac for ever. Costumer service sucks.

we increase rpm to achieve 55hz voltage went up to 190 from 125 at 3100 rpm , I am pretty sure if I can fix the soft valve spring I would get my 3600 rpm

any input
Regards

 

[Birken Vogt]

Is the exhaust spring soft because the valve stem is sticking up higher than it is supposed to be?

 

[plarouche1]

I had to re adjust the valve but it is not sticking. just when pushing on the valves, you can feel a major difference

The part number are the same, they should be identical.

 

[Birken Vogt]

Not sticking, but sticking UP. Is the valve stem higher than the intake valve?

 

[pegasuspinto]

Everyone hating on big G again.

Most manuals at https://www.generac.com/service-support/product-support-lookup/product-support-details?productid=a517ec09-b440-4091-9814-0d68820644a1

Valve spring is OC4391, MSRP under $2 US and shows available at the factory, and a quick google search makes it look very available at lots of places.

His point about the spring being soft and the valve height is that sometimes the valve seat sinks in the head, often because people don't adjust the valves. If the valve stem on the exhaust is much higher/longer then the intake, this may be the case.

Do a compression test, too.

What are you using for fuel? Is the unit configured for your fuel source in both the carb and the computer, and especially if you're using LP, are you sure you got the pressure and volume needed?

 

[plarouche1]

Hi

My LP pressure is steady at 12'' wc as recommanded, my regulation is good up to 175 000 btu.

about the valves, they are available on some spot but not everywhere. I wish I would open the head to go see the valve seat but I have to have the parts before opening it

thanks for your quick reply

 

[pegasuspinto]

If you do that you're pretty much best off buying a whole new head complete, if you can't tear it down first and order just what you need.

 

[mikroland]

Hi, thanks you for letting me register to the forum.
I have a generac 8kw 0056100, the voltage between L1 and L2 is 125 volts ac, and it is 68 volts between neutral and line, the voltage between the capacitor winding is 1,5 volts ac, without capacitor present, with capacitor present it is around 125 volts , capacitor test good, good fluke multimeter, but I am not sure if it worth fixing. I bought it use, the seller had it connected to 5psi propane, guess what happened, he blow out the mixing box. I had it repair and run the generator the 1/2 psi. motor run good
power is low thanks for the advise. ( ps the generator is alone, no transfer box) the seller didn't have it.

Thanks in advance for your input

So this genset doesn't have a DC excitation circuit?