Generac Generator Problem

[Conquistador]

Ok, here's the story. During the Ice storm of 2009, my parents had a natural gas fired Generac generator hooked to their house. They lost power for around 13 days and the generator ran pretty consistently. After the ice storm, they tried to restart the generator for its normal run interval and it wouldn't start. After playing around with it, I got the generator to run but it seemed to have a miss. They called their local generac dealership who sent techs out to look at the generator. They indicated that the engine in it had bent a rod somehow. Instead of fixing the generator, my parents bought a new one and gave the old one to me to fix or do whatever with. My question is, could someone who has typical small engine repair skills work on the engine? I know little about the difference between natural gas fired and regular pump gas fired engines? What do you guys think? Thanks!!

 

[bg71361]

Has that got the 1 liter motor? Any competent machine shop should be able to handle it for you. Did they offer a suggestion as to how the rod got bent? I could see if it was running on gasoline and filled one of the cylinders it would hydraulic, but on natural? Makes me wonder what caused it.
Good luck!
Bill

 

[brandoro]

I don't think there is much difference, if any, except for the fuel delivery method. I think the natural gas ones run different spark plugs.
How big an engine is it? If it is a small air cooled engine then a small engine repair guy will be able to fix it, if it is a 4 cylinder liquid cooled engine then an automotive mechanic would do better with it.

 

[gpflepsen]

How old is the generator? Was its life basically that 13 day run? Generac had some multi-year warranties on their units, is this still in effect? What did your parents get for a replacement? Sorry for all the questions and not much advise.

I have been researching backup generators and considered Generac until my findings began to sway me towards Kohler.

 

[Kubota-guy1911]

There is very little difference between a gasoline and natural gas or LP fueled engines. I have converted several old Continental 602 engine generators from gasoline to LP at work, and a small 9HP B&S OHV engine to natural for myself. The conversion involved changing the carburator and being certain the fuel/air mixture wasn't running lean which would burn the valves. We also gave them a thorough tune up including checking valve clearances.

kj

 

[Wildbill34]

How old is the generator? Was its life basically that 13 day run? Generac had some multi-year warranties on their units, is this still in effect? What did your parents get for a replacement? Sorry for all the questions and not much advise.

I have been researching backup generators and considered Generac until my findings began to sway me towards Kohler.

For what its worth. I have been running a 15k Generac for 7 years now and have never had a problem with it. There have been a few times where it needed to run for 4 or 5 days. I just have the oil changed yearly and replaced the battery once. Outside that, works like a charm. However, I wished I got to 200 amp transfer switch when I bought it. But didn't want to spend another 1500 at the time.

 

[Travelover]

Something doesn't sound right - engines don't just bend rods unless there is some trauma - over revving, sudden stop, rod bearing seizing up, etc. I suspect that once you get into it you will find other damage that explains the bent rod.

 

[Transit]

Something in the original post that dose not sit well, is that the generator ran for 13 days without issues and when used again had a bent rod. I think that sometime in that 13 day period the rod bent and the engine continued to run. You must weigh the cost of repair against the cost of replacement. If the repair/re-build is more than 50% of the replacement, than replace the engine.

 

[RoyJackson]

Something in the original post that dose not sit well, is that the generator ran for 13 days without issues and when used again had a bent rod. I think that sometime in that 13 day period the rod bent and the engine continued to run. You must weigh the cost of repair against the cost of replacement. If the repair/re-build is more than 50% of the replacement, than replace the engine.

Yeah, that does sound odd. However, the engine may have lost timing when the parents tried to restart it (meaning the piston may have hit a valve...rods don't just bend on their own).
There's a good possibility the crank may be damaged too, so a total teardown to check the engine out would be justified. Since the genny is a freebie, putting some money into it might be worthwhile even if it means replacing the engine.

 

[Gator6x4]

Ok, here's the story. During the Ice storm of 2009, my parents had a natural gas fired Generac generator hooked to their house. They lost power for around 13 days and the generator ran pretty consistently. After the ice storm, they tried to restart the generator for its normal run interval and it wouldn't start. After playing around with it, I got the generator to run but it seemed to have a miss. They called their local generac dealership who sent techs out to look at the generator. They indicated that the engine in it had bent a rod somehow. Instead of fixing the generator, my parents bought a new one and gave the old one to me to fix or do whatever with. My question is, could someone who has typical small engine repair skills work on the engine? I know little about the difference between natural gas fired and regular pump gas fired engines? What do you guys think? Thanks!!

Natural, LP or Gasoline engines are basically the same. The method of fuel delivery is different. From your description above it sounds like a valve was damaged in the 13 day run period. The coating on valves used in a Natural or Lp engine is different than ones in a gasoline engine to prevent damage during long runs. The valves crack or burn because of the lean burning of Natural or LP Gas. If you got the engine to run and did not hear a knocking sound I would bet on valve damage.

If you have basic small engine skills, yes you can repair the engine. You can even purchase a carburetor to replace the Natural Gas supply system. If you have LP gas you can re-jet the Natural Gas delivery system.

 

[Conquistador]

Wow, thanks guys. I come back after a long weekend and these are great replies. There is a chance that the oil ran low but that is debatable. It is one of the larger stand alone type of generators that has the v-twin type of configuration. When I got it running, I thought I heard the valves chatterining alot. The generator was not old, 4-5 years at most I believe. The warranty by Generac had just run out, so they couldn't get it fixed through the company which is why I now have it. As far as what the technicians asked, from what I could understand, they were more concerened about unhooking it, taking it to their shop, and making sure they knew what method of payment my parents would use. I wonder how hard it would be to swap engines??

 

[Gator6x4]

You did not say what type/kind of engine the generator is equipped with. I have seen the rocker arms work loose after pro-long operation on some B/S engines. A simple test would be to remove the valve covers, spin the engine over and watch the valve train. Another test would be to remove the spark plugs and place your finger in the spark plug hole and spin the engine over (with starter) and see if the compression feels the same on both cylinders.

 

[jburd964]

I saw you post and no it's almost a year old but I have a engine for Make offer - 15 kW Generac 04390-3
I have a '05 Generac 04390-3 (13 kW NG, 15 kW LP) the windings went bad. The motor may have had hundred hours. The only other thing I know of wrong with it is the solenoid is weak. I was going to shoot video of it running but the solenoid dis-engages when engine load's up compression. I have complete unit the only thing I've done is removed the rotor and stator, figuring it wouldn't be worth the cost of shipping. But it is available if wanted. If you have any questions drop me a line. I live in S. W. Louisiana.