Mini related but also general auto:

When I was a kid with my early cars we would pull the plugs, clean them with emery and/or a fine file re-gap the points and provided the centre electrode hadn't worn so round and disappearing into the porcelain and the other electrode wasn't so thin that it snapped off in the adjusting we'd stick them back in and all as OK The garages also had a little box thing that they would stick the tip of the plug into and sand blast the ends clean and it had some electronics to check the insulation and spark intensity as well.

Take any modern car in for a service these days and the plugs get changed regardless of how good and clean they look. It's even implied that if they are not changed then damage to the engine will result.

Is this just a ploy to sell plugs and because mechanics can't be bothered spending the time re-gapping? Can any damage result from using old plugs properly set up?

_________________
David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

Nope no problem at all, aircraft piston engine spark plugs are still cleaned due to the price of new plugs. But seriously, new plugs are dirt cheap for us. Be careful when you do buy yer plugs though. The gap on them may not be correct from the factory.

I even found one on my old car after I'd had them for about 5000 k's where the core of the plug hadnt been inserted correctly in the factory. The centre post was prolly about 1/8 inch out of position

_________________
"He's always been a dickhead, He always is a dickhead, He will always be a dickhead. So stop complaining when he acts like one."

on an A series, you can clean and gap the plugs and in some cases mod them to better work with the other mods you've done. Run at 0.8 as this will work best. I have seen "V" tip mods on a hill climber. The owner swears the dyno run showed better torque.

As to new engines, you may be concerned to know that some management systems use the spark plug arc resistance to retard timing and modify fuel injection. Using an aftermarket plug or gapping out of spec could land you in deep doo doo