Synthetic oil (or maybe oil additive ?) for small gasoline powered portable generator ?

Joined
Mar 11, 2021
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Hi. Does anyone have any thoughts about using synthetic motor oil in a small gasoline powered portable generator (approx 6Kw output ?). The generator is rarely used (it gets started and briefly run under a modest load, followed by a brief cool down period) a few times a year to confirm it still works and has been run less than 5 hours in over 10 years.) I occasionally change the oil and am about to do so again.

I'm thinking a high quality synthetic motor oil might degrade less during storage ? The manual for the generator calls for 10W30 oil for the likely temperature range (this is somewhat unfortunate as none of my motor vehicles use 10W30.)

Maybe there is a oil additive that might also be useful ?

Any thoughts ?
Thanks
 
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Forget using an oil additive. I'm guessing you know to turn the petcock off and let the engine run until it dies so the carb wont get gummed up.
The generator wont be picky about the oil. I don't stick to any one brand and always change my mind.
 
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The only engine manufacturer that I've ever seen that recommended NOT using synthetic motor oil was my old HONDA HR215 mower. I never did figure out why.
 
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Those generator engines probably don't use more than a quart or so of motor oil. Check your capacity.

Buying the odd quart of a good synthetic of your choice shouldn't break the bank. Just to give you an idea, most small push mower engines don't even hold a full quart, and dumping a quart in them during a change will overfill them and cause big problems.

In my yard/home stuff after break-in I usually run Pennzoil Platinum. Any good synthetic will work in those applications these days. (Vehicles are a different matter, and my Ranger gets Amsoil.) Unfortunately, small yard/home engines today are too often built to be disposable and it costs more to fix than to replace them, so going ultra-premium for synthetic oil in those won't make much difference.
 

Big cat

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Joined
Mar 11, 2021
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Forget using an oil additive. I'm guessing you know to turn the petcock off and let the engine run until it dies so the carb wont get gummed up.
The generator wont be picky about the oil. I don't stick to any one brand and always change my mind.
Thanks.

Yes at the end of my periodic tests, I turn of the fuel valve / petcock and let the engine run until it seems to be starved of fuel. I also use STA-BIL fuel stabilizer in the small amount of ethanol free gasoline I keep in the fuel tank. (I keep other fresher gasoline on hand in case I actually need to run the generator for more than a brief test. )
 

Big cat

Thread starter
Joined
Mar 11, 2021
Messages
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Those generator engines probably don't use more than a quart or so of motor oil. Check your capacity.

Buying the odd quart of a good synthetic of your choice shouldn't break the bank. Just to give you an idea, most small push mower engines don't even hold a full quart, and dumping a quart in them during a change will overfill them and cause big problems.

In my yard/home stuff after break-in I usually run Pennzoil Platinum. Any good synthetic will work in those applications these days. (Vehicles are a different matter, and my Ranger gets Amsoil.) Unfortunately, small yard/home engines today are too often built to be disposable and it costs more to fix than to replace them, so going ultra-premium for synthetic oil in those won't make much difference.
Thanks. I'm more interested in using synthetic oil as I am hoping it might last a bit longer sitting in the crank case than normal oil ? I really don't know if this is the case or not ?
 
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The only engine manufacturer that I've ever seen that recommended NOT using synthetic motor oil was my old HONDA HR215 mower. I never did figure out why.
My guess is it was a holdover from the early days of synthetics, synthetic oil in the beginning was kind of known for poor elastomeric compatibility, excessive seal swelling, "melting", and shrinking/rotting seals were a problem for early synthetics until they worked out standards for elastomeric compatibility.
 
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The only engine manufacturer that I've ever seen that recommended NOT using synthetic motor oil was my old HONDA HR215 mower. I never did figure out why.
That may have been one of the first of the overhead cam designs with the timing belt running in oil, and they weren't certain about oil compatibility with the belt. It turns out synthetic was not a problem, and a typical 6 kW Chonda generator is not of that design anyway.
 
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My Briggs power washer is in the same boat as your generator. I run what ever leftover synthetic I have left over from oil changes. Run a stabilizer in the gas and make sure to run the carb dry between operation cycles. If it doesn’t have a shut off valve add one. It’ll save the carb from gumming up.
 
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Hi. Does anyone have any thoughts about using synthetic motor oil in a small gasoline powered portable generator (approx 6Kw output ?). The generator is rarely used (it gets started and briefly run under a modest load, followed by a brief cool down period) a few times a year to confirm it still works and has been run less than 5 hours in over 10 years.) I occasionally change the oil and am about to do so again.

I'm thinking a high quality synthetic motor oil might degrade less during storage ? The manual for the generator calls for 10W30 oil for the likely temperature range (this is somewhat unfortunate as none of my motor vehicles use 10W30.)

Maybe there is a oil additive that might also be useful ?

Any thoughts ?
Thanks

Synth is fine.

Ive done it for 20+ years, in everything from sub zero conditions to scorching desert heat.

ID leave the additive at the store.No need.

In my current fleet now -

2 honda 2K's
1 honda 2200
Yamaha 3000iseb
Kohler 20K whole house
Powertech 8KW diesel
2X CAT 15KW (work backup units.

These get a range of whats on the shelf but its all at least group III 0W-30 to 15W-40 (with 0W-40 being the most common sump)
 
Joined
Apr 6, 2022
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I run 5W40 (primarily Shell Rotella T6... but I guess the "supply chain" has kicked in with it... it is disappearing off the shelves around here) in my generators that may need to be started in the dead of winter. In my "summer" equipment I run 15W40 (primarily Mobil 1300 Super... again disappearing from the shelves all of a sudden.)

No engines have complained yet.
 
Joined
Jan 9, 2008
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684
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WV
I have never come across any situation where an oil additive was necessary or even a good idea. Oils are very complex blends and don't need any additive to "improve" them. I am not talking about engine assembly lubes, and break-in oils etc. that are used on newly rebuilt engines, I'm talking about every day use engine oil.
Let's see over the years, there's been Slick50, ProLong, STP, Rislone, Lucas Oil Additive, ... etc. anyone ever have any proof of an engine saved, or even running better with any of these? Not seat of the pants dino either, I mean real proof, ... can't be done.
 
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