I'd say they look ok as far a diagnosing how the engine is running; rich, lean, etc. but they should be changed at 10k. I change mine as part of my winter layup at less than 10k. They are cheap.




a. A wet, black and shiny deposit on plug base, electrodes and ceramic insulator tip indicates an oil fouled plug. The condition may be caused by one or more of the following: worn pistons, worn piston rings, worn valves, worn valve guides, worn valve seals, a weak battery or a faulty ignition system.

b. A dry, fluffy or sooty black deposit indicates an air-fuel mixture that is too rich.

c. A light brown, glassy deposit indicates an overheated plug. This condition may be accompanied by cracks in the insulator or by erosion of the electrodes and is caused by an air-fuel mixture that is too lean, a hot running engine, valves not seating or improper ignition timing. The glassy deposit on the spark plug is a conductor when hot and may cause high-speed misfiring. A plug with eroded electrodes, heavy deposits or a cracked insulator must be replaced.

d. A plug with a white, yellow, tan or rusty brown powdery deposit indicates balanced combustion. Clean off spark plug deposits at regular intervals.

 

I forgot to mention that these photos were taken after running 3,000 miles (installed at 15000 miles on odometer) with a high flow air cleaner and free flowing slip on mufflers installed. No modified fuel management.

 

Thanks for posting. This proves the stock ECM is doing what it's capable of doing. Plugs look Good!!! If it's running good don't fix it until it's not...LoL

 

They look great to me. Carry on!

 

I change mine at every oil change. They are cheap enough.

 

The Manual says replace them at 20K. Why waste your money if they don't need changing???