Righto, My mate Mark has a 1966 beetle 6v one owner.
The plugs are sooting up every few weeks and he wants to know what is the problem and what is the solution?
He runs 95 octane, normally Caltex and BP.
Compression is good, leads, points, cap, rotor, coil and condensor are all new.
What's happening?

My first guess is it is running rich

I would start with a good tune up - timing, valves and setting points

Go for a drive and then check your plugs again
They should not be black a d should all be the same colour

If still black I would check for a vacuum leak.
Could be some PO as richened it up to mask a lean leak somewhere

A way - that's a starter for you.

Barry

yep I'd be looking at running rich for one
How's the smoke n pipe colour from the exhaust?

Thanks for the replies to date.
Timing, valves and points have all been done.
There does not appear to be a vacuum leak.
The carby has been off and cleaned out.
There is control with the mixture screw, winding it all the way in and then out about one and a half turns.
The NGK plugs soot up and it starts missing and only a new set of plugs fixes the problem.
No smoke issues.
The pipes are blackish.

when you wind the mixture screw in does the motor start to die?
You find the sweet spot at 1 1/2 turns out??

If all the tuneup issues are ok...
I would be looking at float level, Condition of needle and seat, Jet size.

put in some Bosch W10AC plugs and it will fix your problem.

Will try those plugs, thanks.
Probably go for 12v conversion to help the spark.
Thanks for all the replies.

I get the same thing after a couple of weeks if I've been doing a lot of short trips around town. A short drive on the highway sorts it out. Lately I find myself taking the "long way" to get everywhere just to prevent the problem, especially with the arrival of cooler weather when choke tends to be on for longer.

I have no pre heat to the inlet manifold, which doesn't help either.

Regards,

Matt.