2012 spark plugs

[outdoors4evr]

I replaced the spark plugs in my 184. I think the last time these were changed is 2012. These are Champion D21. The tractor does mostly mowing, and a little snow pushing.

Cylinder #1 & 4 are white
Cylinder #2 & 3 are blackened

[outdoors4evr]

Do these look fairly healthy?

[Larry B]

For a 184 those look pretty good. The D21 plug is what i run in mine.

[Bill V in Md]

Looks like there is a problem with #2 and #3 plugs. But it’s hard to know if this is a chronic problem or a relatively recent issue. How was the tractor running? Was it running rough with a miss or two? Maybe that’s why you changed them. Eight years is a pretty decent life though. Could be an ignition or valve issue, and you probably know better than me how to troubleshoot that. My only other comment is regarding the corrosion on the metal surfaces. Seems to be excessive, but maybe the tractor lives outdoors in a relatively humid environment. Hopefully it is attributed to that and nothing more.

[outdoors4evr]

Tractor is running well, spark plugs changed due to time and opportunity (hood is off) rather than need.
The tractor had to live outdoors while we moved and built a garage. (3-car so the Tractor and other toys have a home)

Any thoughts on why the center two cylinders collect more carbon than the outboard two? Its not like I can adjust the fuel supply to each individual cylinder.

[Eugene]

Spark plugs look fine specially after 8 years.

Compression tests during the tune up?

[outdoors4evr]

I didn't do compression tests because the engine got a lower end rebuild with new pistons and rings in 2012. No work was done on the valves other than check the valve clearance.

[Donegal Cub]

PLUGS LOOK FINE TO ME,

[gitractorman]

I'd say those look perfectly fine for 8-years old!!! Throw some new ones in, a shot of SeaFoam to each cylinder prior to replacing, and run for another 8 years!

There's not much reasoning to the carbon buildup. One cylinder could be getting a little too much fuel, valves could be adjusted just a little differently, one plug could just be a little cooler than the others, really hard to say. Honestly though, those plugs don't look bad at all.

[Rick Spivey]

To my knowledge and limited experience, all tractors are set up to run just a wee bit rich. I suppose the idea is that when loaded the mixture is correct, and richer is better than leaner on older equipment. Since most of us don't work a cub as hard as the original owners did when farming, I always see a bit of black on the plugs of a good running engine. To me, three of the four have that brown color you hope to see, so I would just put new plugs and don't change much of anything.

[outdoors4evr]

We got a new pile of white stuff blanketing the ground yesterday. I did about an hour of snow pushing. She ran well on the new NGK plugs and the clutch worked perfectly. The hood is still off as I am waiting on a new air filter. Tractor got warm enough to burp a little coolant out of the overflow tube. (added a bit of coolant for the winter, just above the tubes inside the radiator)

[SONNY]

Your old plugs look fine!---I won't show you the ones in my 185!