jeez, this threads all over the place...
venice and joe, my bike used to surge all the time, not bad enough that i cared, and almost always under load. i figured it was because it was too rich. from past experience with mikuni sidedrafts on 4cylinders, the car would "burble" from getting to much gas. it sounded like it was drowning.
applying that to my bike, after i built my candleholder velocity stack, the bike rarely 4 strokes at all. even up super steep hills. it'll slow down from the load, but it doesn't bog, 4stroke, or burble. just keeps on chugging.
every now and then it gets that little surge, but it'll power right through it. so what worked for me, was to make it breathe. i didn't lean it on the fuel, i just increased the air. my clip's at the second from the top notch. and it is (top notch, that is
as for you other guys, skinnier tires have less rolling resistance, but not necessarily less traction (look at a road racer going around a corner at 50mph,) they're smoother and faster, on smooth and fast surfaces.
fatter tires cushion the bumps better, keep you upright at slower speeds, and provide better traction in harsher conditions.
off road "knobby" tread leads to a bumpier ride, giving more vibrations you'll most likely feel in the handlebars, and will ultimately be slower than a smoother tread, but work great if you go off road, or in sand and gravel.
for cruisers, a fat street tread is probably the best way to go. plus, it just looks right.
the best tire for wet leaves, oil, slimy gutters, and ice, are ones clean enough to not mess up your carpet when you're home watching tv during these conditions.