How often to change oil in unused portable generator?

It's lack of use that's the problem, not age of fuel. The fuel needs to be moving inside that carb not just sitting for months on end.
 
another Todd said:
I have multiple generators that seldom get used anymore. I change the oil about every 5 years. I leave them empty of fuel, run dry, and keep 15 or 20 gallons of stabilized fuel in sealed tight fuel cans and rotate that fuel every 18 to 24 months by dumping that fuel in my truck and refilling fuel containers. Never an issue.
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Same. Except I use the fuel in my twin cylinder lawn mower.
 
thastinger said:
I would store gas in it at all if it is tri-fuel. Drain it and leave it dry. Get some marine fogging oil and spray some down the spark plug hole, turn it over a few times, put the plug back in and put the piston at TDC. Then forget about it until you need it.
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For the engine, that's not bad advice.
For the generator, that's terrible advice.

Generators units are unique in that they need to be run at least a few times a year to exercise the power-head (the electrical power producing part of the generator unit) to keep the magnetic fields fully excited. It's a very good idea to run a generator at least twice a year (spring/fall), while under moderate load (half the rated output), to keep the electrical portion in great shape. Gens that sit for many years without use can lose their field effect for start up, and essentially become nearly worthless. It's far easier and better for the unit to be run under moderate load twice a year.

I have come across used generators sitting in garages and barns which can start the engine, but produce no electrical energy. This is because the field wasn't exercised during storage. The longer they sit unused, the greater this effect. (While it is possible to be what's called a "bump start" of a dead generator power head, it's not something the average Joe is going to be able to do easily, and it's a total PITB because it has to be done each and every time the field has to be excited after the previous shutdown).

Best advice I can give is this:
- run gen in spring and fall, for 30 min per session
  1. first 5 min with no electrical load for easy warm up
  2. 20 min under 1/2 the rated load (use a hair dryer or some halogen lamps)
  3. last 5 min with no load to allow engine and powerhead to cool down
- then shut down; check oil level so it's good for the next use; drain gas from carb
- cover and keep in a dry place
I have used this practice for all my gensets. I have some that are nearly 30 years old and still run great; both engine and powerhead. This system will have your genset always ready for the next use, and keep it in fine shape for decades. I change the oil about every 5 years, unless I have an extended use run of a long duration of hours; then it would get an OCI.
 
dnewton3 said:
For the engine, that's not bad advice.
For the generator, that's terrible advice.

Generators units are unique in that they need to be run at least a few times a year to exercise the power-head (the electrical power producing part of the generator unit) to keep the magnetic fields fully excited. It's a very good idea to run a generator at least twice a year (spring/fall), while under moderate load (half the rated output), to keep the electrical portion in great shape. Gens that sit for many years without use can lose their field effect for start up, and essentially become nearly worthless. It's far easier and better for the unit to be run under moderate load twice a year.

I have come across used generators sitting in garages and barns which can start the engine, but produce no electrical energy. This is because the field wasn't exercised during storage. The longer they sit unused, the greater this effect. (While it is possible to be what's called a "bump start" of a dead generator power head, it's not something the average Joe is going to be able to do easily, and it's a total PITB because it has to be done each and every time the field has to be excited after the previous shutdown).

Best advice I can give is this:
- run gen in spring and fall, for 30 min per session
  1. first 5 min with no electrical load for easy warm up
  2. 20 min under 1/2 the rated load (use a hair dryer or some halogen lamps)
  3. last 5 min with no load to allow engine and powerhead to cool down
- then shut down; check oil level so it's good for the next use; drain gas from carb
- cover and keep in a dry place
I have used this practice for all my gensets. I have some that are nearly 30 years old and still run great; both engine and powerhead. This system will have your genset always ready for the next use, and keep it in fine shape for decades. I change the oil about every 5 years, unless I have an extended use run of a long duration of hours; then it would get an OCI.
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Yeah, I concur, wasn't even thinking of the power head.
 
I don't think anyone asked - how did you break this generator in?

If its broken in and the oil was then changed, yes I would do several years. If you haven't - I would - then go several years.

I run mine every 3 months and use only E0 fuel. It has a fuel shut off and I just shut that and let it run dry. If yours doesn't have a fuel shut off I would look into adding one.
 
I broke it in at 5 hours per the book, ran it with a 2000w load. Oil that came out was a mess, full of glitter, and the magnetic plug was caked

Oil change after that was nice and clean though

I generally don't run it dry, but I do just drain the carb bowl since it has a drain screw, and throw it back in the tank. I also added a T to the fuel line after the shutoff to a separate fuel line with another shutoff that is about 10 inches long, so I can easily drain the entire tank. Every 6 months I rotate it out
 
I've had good luck with simply by draining the fuel tanks on my small engine powered equipment and then running the engine until it runs out of fuel. I don't care what type of gas I buy, I drain it if it is going to sit for an extended period of time and run the engine until the device stalls..
as far as when to change the oil, if it is a low hour application, it probably doesn't matter if a person does it or doesn't.
 
MSCH said:
I've had good luck with simply by draining the fuel tanks on my small engine powered equipment and then running the engine until it runs out of fuel. I don't care what type of gas I buy, I drain it if it is going to sit for an extended period of time and run the engine until the device stalls..
as far as when to change the oil, if it is a low hour application, it probably doesn't matter if a person does it or doesn't.
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If its a steel tank you may be better off leaving them full. I've found that the anti-rust coating on tanks like the Wavian NATO can's will degrade and dry out with no gas touching them, so its best to leave them full. Same with rust developing when dry from the humidity on bare tanks
 
SupremePossum said:
If its a steel tank you may be better off leaving them full. I've found that the anti-rust coating on tanks like the Wavian NATO can's will degrade and dry out with no gas touching them, so its best to leave them full. Same with rust developing when dry from the humidity on bare tanks
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maybe for you, but in my experience draining the tank and running the engine until the carb is dry has worked well.. my generator is 12 years old, has a steel tank, I'm in an exceptionally humid environment ( FLA) and I have had no issues with my gen set doing it the way I have been doing.
 
dnewton3 said:
For the engine, that's not bad advice.
For the generator, that's terrible advice.

Generators units are unique in that they need to be run at least a few times a year to exercise the power-head (the electrical power producing part of the generator unit) to keep the magnetic fields fully excited. It's a very good idea to run a generator at least twice a year (spring/fall), while under moderate load (half the rated output), to keep the electrical portion in great shape. Gens that sit for many years without use can lose their field effect for start up, and essentially become nearly worthless. It's far easier and better for the unit to be run under moderate load twice a year.

I have come across used generators sitting in garages and barns which can start the engine, but produce no electrical energy. This is because the field wasn't exercised during storage. The longer they sit unused, the greater this effect. (While it is possible to be what's called a "bump start" of a dead generator power head, it's not something the average Joe is going to be able to do easily, and it's a total PITB because it has to be done each and every time the field has to be excited after the previous shutdown).

Best advice I can give is this:
- run gen in spring and fall, for 30 min per session
  1. first 5 min with no electrical load for easy warm up
  2. 20 min under 1/2 the rated load (use a hair dryer or some halogen lamps)
  3. last 5 min with no load to allow engine and powerhead to cool down
- then shut down; check oil level so it's good for the next use; drain gas from carb
- cover and keep in a dry place
I have used this practice for all my gensets. I have some that are nearly 30 years old and still run great; both engine and powerhead. This system will have your genset always ready for the next use, and keep it in fine shape for decades. I change the oil about every 5 years, unless I have an extended use run of a long duration of hours; then it would get an OCI.
Click to expand...
Not exactly arguing with this advice; but, it's the gummed up carburetor from no use that bricks your generator, not power head issues.
 
My dad had a champion generator, he changed the oil about once every 5 years or so. He used it twice a month for a few hours. After 15 years or so it still ran, but wasn't as powerful as it used to be. He got a new inverter generator with more power and better fuel consumption and gave the old one away. For the last year or so before he gave it away it would always start first pull, because once you pulled the cord the engine would spin for almost 2 seconds or until it fired off. I don't think it had much compression left
 
dumkid said:
My dad had a champion generator, he changed the oil about once every 5 years or so. He used it twice a month for a few hours. After 15 years or so it still ran, but wasn't as powerful as it used to be. He got a new inverter generator with more power and better fuel consumption and gave the old one away. For the last year or so before he gave it away it would always start first pull, because once you pulled the cord the engine would spin for almost 2 seconds or until it fired off. I don't think it had much compression left
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Thats the automatic compression release that reduces the starting pull
 
I got a portable generator that probably last had the oil changed maybe in 2017, probably has sj rated rotella 15w-40 in it.
It's only been ran a few hours since 2015.
 
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