Onan QG 4000 RPM

Mike Pearson · 06-16-2020, 08:31 PM

The one i had in my trailer before the 6.5 was a 4.0 CCK. On the name plate it said
Onan division of Studebaker. It still ran and made power when I pulled it out. I bet it has 20k hours on it.

Jeff Niceswanger · 06-23-2020, 02:33 PM

If anybody is looking for a 4000 I have one.I bought it new to replace the one in our Class C and after 3 seasons it quit charging. A trip to the Onan Bridgeway dealer told me it was un reparable. I bought another new one, but while waiting on it to come in I went ahead and had a look at my old ( torn apart from Onan) unit. All that had happened, is the brushes had worn, twisted inside the brush holder, and mangled up one of the two small wires going to the brushes. Other than some of the insulation being removed from the wire, it was usable. I just put some small heatshrink on the wire, bought a new brush holder/brush set, and re assembled. It ran flawlessly on the bench and charges just fine. The thing looks new, its not even dirty. I'd like to get it out of my road , its here in the garage .. 700.00

740 297 0817

Rich Biebel · 06-23-2020, 07:22 PM

I pulled one out of a 2010 Class C today..

Around 2000hrs on it. Starter broke but the machine is a mess and had NO oil in it. I turned it over by hand at the blower wheel and it has NO compression. With no oil it probably broke the connecting rod.

Repairing the engine on a machine in extremely poor condition makes zero sense. It could have destroyed a lot inside that engine and replacing the complete engine is an even worse idea from a cost standpoint.

I ordered the owner a new machine. I will go pick it up as soon as it's ready for pickup and install it...1 or 2 days at most

The owner will be happy.....New generator.....But sir, please check the oil and leave the access door in place !!!

It says both things in big bold letters right on the front.....

A new style 4KY 4000 watt Onan does NOT have a low oil level shutdown....it will break the engine's connecting rod every time when oil gets so low that there is nothing visible on the dipstick....Seen it many times.....ZERO maintenance....for 2000hrs ? I am not sure on that one....

The owner actually asked me if the machine has oil in it like a car engine !!!

06-16-2020, 08:31 PM	#1
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,449 Likes: 615 Liked 1,926 Times in 579 Posts	Re: Onan QG 4000 RPM The one i had in my trailer before the 6.5 was a 4.0 CCK. On the name plate it said Onan division of Studebaker. It still ran and made power when I pulled it out. I bet it has 20k hours on it. __________________ Mike Pearson 2485 SS

06-23-2020, 02:33 PM	#2
Jeff Niceswanger Senior Member Join Date: Jul 2003 Posts: 894 Likes: 685 Liked 1,031 Times in 368 Posts	Re: Onan QG 4000 RPM If anybody is looking for a 4000 I have one.I bought it new to replace the one in our Class C and after 3 seasons it quit charging. A trip to the Onan Bridgeway dealer told me it was un reparable. I bought another new one, but while waiting on it to come in I went ahead and had a look at my old ( torn apart from Onan) unit. All that had happened, is the brushes had worn, twisted inside the brush holder, and mangled up one of the two small wires going to the brushes. Other than some of the insulation being removed from the wire, it was usable. I just put some small heatshrink on the wire, bought a new brush holder/brush set, and re assembled. It ran flawlessly on the bench and charges just fine. The thing looks new, its not even dirty. I'd like to get it out of my road , its here in the garage .. 700.00 740 297 0817 __________________ Jeff Niceswanger 3740 SS Last edited by Jeff Niceswanger; 06-23-2020 at 06:09 PM.

06-23-2020, 07:22 PM	#3
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	Re: Onan QG 4000 RPM I pulled one out of a 2010 Class C today.. Around 2000hrs on it. Starter broke but the machine is a mess and had NO oil in it. I turned it over by hand at the blower wheel and it has NO compression. With no oil it probably broke the connecting rod. Repairing the engine on a machine in extremely poor condition makes zero sense. It could have destroyed a lot inside that engine and replacing the complete engine is an even worse idea from a cost standpoint. I ordered the owner a new machine. I will go pick it up as soon as it's ready for pickup and install it...1 or 2 days at most The owner will be happy.....New generator.....But sir, please check the oil and leave the access door in place !!! It says both things in big bold letters right on the front..... A new style 4KY 4000 watt Onan does NOT have a low oil level shutdown....it will break the engine's connecting rod every time when oil gets so low that there is nothing visible on the dipstick....Seen it many times.....ZERO maintenance....for 2000hrs ? I am not sure on that one.... The owner actually asked me if the machine has oil in it like a car engine !!! __________________ Rich Biebel S/C 1479 Stock 147R