Anybody else experiencing sparkplugs won't stay clean in lawnmowers running E10 pump gas?

[FordFETruck]

I noticed that for about the last 15 years no matter what lawnmower I've had my hands on, new or old, OHV, flathead, etc the sparkplugs are always coated in either carbon buildup or a dark colored goo that doesn't really resemble oil. The only small engines I've seen that sometimes are an exception are generators or pressure washers that run full throttle high load all the time. Anybody else notice this as well? I never have any troubles with them actually fouling or starting hard, the plugs just look dirtier than they should be.

Here's a pic for example, this spark plug was in service for 14 years in an engine that barely uses any oil at all and is very clean inside. I never noticed this years ago when we had E0 gas in the summertime here, the plugs were always clean and the porcelain having a nice tan color to them. And before anybody asks, the air filters on my equipment are always kept pretty clean so I don't think that's it. I've run several brands, NGK, Denso, Champion, Bosch, Autolite (as pictured) etc they all seem to get the same cruddy look to them and changing heat range hasn't made much difference. The plug in the pic had around 250 hours on it and I hadn't checked it in a couple of years. I put it in my sparkplug tester trying that thing out and saw it arching through the porcelain on the outside, it got replaced anyways. 3 sparkplugs in 48 years, not bad. Anyone else noticing the same thing running E10 pump gas?

 

[Lubener]

That looks like oil fouling to me. I run E10 all the time with Champion J19LM plugs and never had any problems with fouling. If you think it's fuel related, switch back to E0 gas and see. It wouldn't hurt to change your plugs a little more often where it won't break your bank.

 

[CharBaby]

Same here, no issues w/E10

 

[nomas]

I run E10 all the time . No issues .

 

[spasm3]

I run e-10 during the mowing season, and e-0 at the end of the season, so that my equipment has e-0 for winter storage.
If anything, plugs are cleaner with e-10, but not much difference.

 

[97prizm]

I noticed that for about the last 15 years no matter what lawnmower I've had my hands on, new or old, OHV, flathead, etc the sparkplugs are always coated in either carbon buildup or a dark colored goo that doesn't really resemble oil. The only small engines I've seen that sometimes are an exception are generators or pressure washers that run full throttle high load all the time. Anybody else notice this as well? I never have any troubles with them actually fouling or starting hard, the plugs just look dirtier than they should be.

Here's a pic for example, this spark plug was in service for 14 years in an engine that barely uses any oil at all and is very clean inside. I never noticed this years ago when we had E0 gas in the summertime here, the plugs were always clean and the porcelain having a nice tan color to them. And before anybody asks, the air filters on my equipment are always kept pretty clean so I don't think that's it. I've run several brands, NGK, Denso, Champion, Bosch, Autolite (as pictured) etc they all seem to get the same cruddy look to them and changing heat range hasn't made much difference. The plug in the pic had around 250 hours on it and I hadn't checked it in a couple of years. I put it in my sparkplug tester trying that thing out and saw it arching through the porcelain on the outside, it got replaced anyways. 3 sparkplugs in 48 years, not bad. Anyone else noticing the same thing running E10 pump gas?

View attachment 298211

I've never had anything resembling that in any of my push mowers. Maybe try a different temp range plug?

 

[Slick3914]

No, in 21 years I’ve changed the spark plug in my John Deere one time.

 

[Opelman]

I've probably replaced over 100 spark plugs at work this year on Kawasaki, Kohler, Briggs, Yamaha, Loncin, and Kubota mower engines. Maybe 1 or 2 looked what I would call "good". A couple looked nasty like yours, but most were just sooty black. Even the fuel injected motors were ugly. A good bunch of our customers are trained to have their machines in to us for service at 100 hour intervals, Kawasaki I know for sure recommends spark plug replacement then.

 

[NiwradND]

Check the air filter, could be air restricted somehow if mot using oil

 

[BigCahuna]

I run a fleet of 5 mowers that I do the maintenance on, and I haven't had that issue. But here's what I do. When my gas can is empty, I pour some carb / fuel injector cleaner in the gas cam, bout half a bottle. And maybe some mmo if I have that on hand. So every time I refuel, that gas used is treated. I never have starting issues, even the first starts of the season is no problem. I run 10w40 wt oil in my mowers and have no consumption. My oldest mower is 27 years old. And yes I run E-10 gas, because that's all you can get at gas stations here in New Jersey. I keep some gas over the winter in case I have to run my generator. Not alot maybe 4 gallons, and it always starts right up when I test it. That's my story and I'm stickin to it.,,

 

[shortyb]

Too much water. The ethanol is absorbing water and the water laden fuel is combining with the slight amount of oil that migrates past the piston ring(s) in just about all horizontal splash lubed engines. This produces the goo that you are seeing as unlike straight fuel, doesn't burn very well and leaves those deposits. I've seen it happen a lot. Use a fuel additive that "absorbs" or mitigates the water in E10/gasoline so that it will burn cleaner. Also, as mentioned, if you can go up a heat range on the plug (some engines spec hotter or colder plugs), the extra heat may burn off that mess.

Edit; saw where you tried upping the heat range without success. Main thing though, is to keep the absorbed water out of your fuel.

 

[Nessism1]

You lost me when complaining about a 14-year-old spark plug.

 

[50yr Street Mech]

I run HEET red bottle and stabilizer mixed in with my 5 gallon jugs of fuel. That takes care of the moisture and the ethanol from messing up the carbs and fuel lines. Change plugs every 2 years. 14 years is a long time .

 

[Gyro Gearloose]

Champion J19LM plug and 15W40 oil and you have done the best you can to get a clean plug.

 

[Mechanician]

I have never had a problem with E10 causing any problems on my OPE.
The ethanol can only absorb water if it sits vented to the air - long enough.
So use either a well sealed storage container, or don't store gas long term.

 

[fantastic]

My plugs have never looked like that & I've always run 10% ethanol. You have other issues.

 

[ARCOgraphite]

Original plugs in my 34 year old push mower and previous 27 year old snow blower with a Tecumseh SK. If your are not a professional and or not mowing a 1/2 acre plus - never enough hours will be accumulated to require a new plug. Never replace a plug yearly or even at 5 years - It is not "cheap insurance" it is just unneeded "over maintenance" but can it hurt? Yes it can.

- old Arco

 

[Brian123]

I noticed that for about the last 15 years no matter what lawnmower I've had my hands on, new or old, OHV, flathead, etc the sparkplugs are always coated in either carbon buildup or a dark colored goo that doesn't really resemble oil. The only small engines I've seen that sometimes are an exception are generators or pressure washers that run full throttle high load all the time. Anybody else notice this as well? I never have any troubles with them actually fouling or starting hard, the plugs just look dirtier than they should be.

Here's a pic for example, this spark plug was in service for 14 years in an engine that barely uses any oil at all and is very clean inside. I never noticed this years ago when we had E0 gas in the summertime here, the plugs were always clean and the porcelain having a nice tan color to them. And before anybody asks, the air filters on my equipment are always kept pretty clean so I don't think that's it. I've run several brands, NGK, Denso, Champion, Bosch, Autolite (as pictured) etc they all seem to get the same cruddy look to them and changing heat range hasn't made much difference. The plug in the pic had around 250 hours on it and I hadn't checked it in a couple of years. I put it in my sparkplug tester trying that thing out and saw it arching through the porcelain on the outside, it got replaced anyways. 3 sparkplugs in 48 years, not bad. Anyone else noticing the same thing running E10 pump gas?

View attachment 298211

You basically need to take the spark plug off once a year and see if it needs cleaning. 250 Hours on a plug that you have not checked on in a couple of years, I am guilty of that, if it is not broken, do not fix it. Your spark plug tells me you have other issues with this engine. JMO

 

[odie]

Recently checked the 2 CHAMPION plugs of the B&S 22 H.P. Twin-Cylinder and they were clean with the use of non Top Tier 90 w/o E .

 

[Bettez88]

Guys just here to say that spark plugs are cheap…change them more often maybe?