Re: Im going to run a NGK B5HS spark plug....
IMHO a 5 is too hot with the stock timing...and I didn't like a 6 much either. I tried a 9 but it wouldn't clean itself very well on a 32:1 mix and stock timing although it remedied the indications of detonation I was hearing and seeing on the other plugs I tried. I've put about 1200k on a BPR7HIX, a 40:1 mix and slightly retarded timing...at 2110 km the plug is clean, idle is low and smooth and my GPS says I top out at 54 km/h
With regards to how I tweaked the timing...I don't use the key that fixes the magnet rotor to the crankshaft.