Rapid plug failure in Chummy

[Ian Williams]

I agree with Rory and the other's on the point that the plugs are fouled either through oil and or over rich mixture. It is also well known that modern plugs do not have glazed ceramic insulators which, as has been pointed out, make them far more susceptible to fouling. However I don't agree that they can not be recovered. I have successfully on many occasions cleaned plugs in such a condition with brake cleaner and then blasting the insulator with a very fine media. Not always 100% successful but this method works for me most of the time. Obviously you need to fix the root cause or you will be quickly back to square one, and if using sand or glass bead absolute cleanliness is ESSENTIAL, Soda is less of a concern on this point but always successful on really bad plugs.