Stored portable generator

[Fodeman]

I was given a Generac GP6500 portable generator from my neighbor. I found out it has been sitting for 3 years with no gas in the tank. Rather than descaling the inside of the tank (which was heavily rusted), I bought a new tank on ebay.

I disassembled and cleaned the carburetor. What would you guys suggest to do about the upper cylinder? Should I pour a table spoon of oil in the top of the cylinder and let it sit for a while? I also found some marvel mystery oil that I've had on the shelf for a while. Thoughts?

 

[walterjay]

I would just start it up. But that is just me.

 

[jtwrace]

Put oil in it, if it has electric start you can crank it a bit without a spark plug to splash the oil around then light it up.

 

[mobilnissan1991]

Soak the foam air filter in oil and squeeze out the excess, change the spark plug to the proper NGK plug, and change the oil, should take a quart, I suggest Delvac Extreme 15W40 or Mobil 1 15W50. Start it up and put a good load on it for a while then run the fuel out the carb with the on/off valve.

 

[spasm3]

I would do the above, also I would add some oil through the spark lug hole before turning over

 

[MaximumMini]

What I'd do....

Upper cylinder (entire cylinder since you don't know the position in the cylinder where the piston sat all this time)
Definitely pour the MMO in the plug hole and let it sit at least 24 hours.
Chances are that at least some rust has formed on the cyl wall at the rings. If it's bad enough, it could crack the rings when you try to rotate the engine. If it pulls easily by hand, you're probably ok.

Then....
Make sure it has a fresh fuel filter inline.
Fresh oil 100% necessary.
New spark plug.
Then use ONLY ethanol free gasoline and add Stabil MARINE 360 fuel stabilizer.
Once running smooth...check output for voltage and frequency since it's not an inverter genny it must run at the precise speed.
(you may know most or all of this...just added for future visitors who may not)

My 3 cents

 

[Dborch41]

Check around the flywheel and baffles for critter nests, Fievel and friends love to make homes in those tight little spaces. A squirt of light oil in the spark plug hole then pulling the engine over a few times certainly can't hurt, just don't hydro-lock it when you reinstall the plug.

 

[Fodeman]

What I'd do....

Upper cylinder (entire cylinder since you don't know the position in the cylinder where the piston sat all this time)
Definitely pour the MMO in the plug hole and let it sit at least 24 hours.
Chances are that at least some rust has formed on the cyl wall at the rings. If it's bad enough, it could crack the rings when you try to rotate the engine. If it pulls easily by hand, you're probably ok.

Then....
Make sure it has a fresh fuel filter inline.
Fresh oil 100% necessary.
New spark plug.
Then use ONLY ethanol free gasoline and add Stabil MARINE 360 fuel stabilizer.
Once running smooth...check output for voltage and frequency since it's not an inverter genny it must run at the precise speed.
(you may know most or all of this...just added for future visitors who may not)

My 3 cents

Thanks, I'm definitely going this route. I've been using e-free gas in all of my small engines for at least the last couple of years, as well as using sta-bil year 'round. I live in a high humidity area, so

 

[oil pan 4]

If you have 2stroke gas on hand run some of that.
That tank likely rusted because of ethanol gas. When you put it away, run or dump all the ethanol out of it and run some ethanol free gas in it before you put it away, if possible.

 

[spasm3]

I tend to keep my fuel tanks full of non-ethanol in the off season. Keeps moisture out, less room for air, especially with metal tanks.

 

[Fodeman]

Yesterday afternoon, before I installed the new tank, I put a tablespoon of the Marvel mystery oil in the top of the cylinder and let it set overnight. Today I pulled the recoil with my thumb over the plug hole and had good compression. Attached plug wire and grounded the plug the casing. Pulled the recoil again and had good spark. Installed new fuel line and fuel filter. I had already taken off the carb and cleaned it. Put everything together, turned on fuel. First pull with choke on and it started right away . After smoking out my nextdoor neighbor's backyard with the mystery oil in the exhaust , it cleared up and ran fine. All voltages checked out as well.

 

[BC1]

Bold move buying a fuel tank before knowing if it ran and made power.

 

[JimPghPA]

The Generac GP6500 is not an inverter type generator.

If the armature of the electric generation section looses residual magnetism by sitting unused too long, you have to excite it with the engine running to get it to work again.

Watch yt videos about how to do that.

 

[Lubener]

Most likely there isn't a steel cylinder sleeve so there is no reason to flood the combustion chamber with oil. Service the engine and get in the habit to run it atleast once a year to keep the generator polorized.

 

[Fodeman]

Oh, I will run it more often than that. I also have a Generac 7500 EXL that I run a monthly load test on with a 1500w portable heater. I intend to do the same with this one. Also, a full tank of e-free gas with Stabil has always been a pet peeve of mine.