How can you tell if the spark plug is still good? Any good ways of testing or any sites with pictures.. I have some NGK Sparkplugs in there, I dont know if it is stock or has been added, I just got this car. They look clean but look completely different than a normal plug... So how do I tell if it needs to be replaced?

 

if they are clean, then they should be fine

and yeah rotary plugs are a bit different lookings usually

 

Yeah, as long as they are clean and not fouled, and the edges of the center electrode still look "sharp"(i.e. not worn with rounded edges) they are probably ok to reuse. And yes, they do look different than most plugs with a center ground strap.

 

i think it's the ngk b 10's theat look like normal plugs