Originally Posted by Nitrohorse
There shouldn't be any metal particles on your spark plug. Metal particles are a sign of something is wearing in the engine.
And a magnet will will only attract ferrous metals. Your particles are aluminum.
You could have a broken ring that's "machining" a groove in the cylinder wall each time you start the engine.
If it was my engine, I'd tear it down to see what's causing the metal particles.
No doubt, if there's metal, there's a problem.
Not sure if the liners are magnetic (nikasil) but it could be that, the bushing in the wrist pin, (bronze of sorts) or piston skirt (aluminum).