I have carbon coated spark plugs, which means I am running rich, correct?
I have a 34 pict 4 carby, how do I adjust the mix to correct this? I only have manuals for earlier carbies, I think I know which is the fuel mix screw (higher up than the earlier models on the side just below the auto choke?). But which way and how much do I turn it?
I guess I should replace the plugs too right?

In a word.....not really...
what was once a simple analysis now is complicated by the " Crap Fuel " available.
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One suggestion is to ensure the tank is completely (purely ) filled with Premium Unleaded and run this for some time before doing the Plug Cut. (checking the plug colour ).
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The problem is that Lead Replacement fuel leaves soot on the plugs now matter how lean it is.
Add to this the possiblity that you could be being fed a mixture ethanol with your fuel which means " I dont know what " for plug colour.

do a search for Rob (Aussie bugs site)

he has a wonderful site on tuning

OK, thanks,
I don't use LRP though, only unleaded and every now and then premium (when I'm feeling richer than usual)

I may not have located the fuel mix screw correctly, any one be able to help me, which side of the carby, what is it near?

should be the one with the spring set it about 1 1/2 turns out from fully in then tweak it from there