pilot screw

1980 kawasaki 750 bored out to 810. 
I finally have the bike jetted so it runs really good under power since the rebuild. I look at the sparks plugs and they look good but show signs of fuel not being fully burned as the ring around the electrode has excessive carbon on it. The bike also seems to surge slightly and not run as smooth as it should while cruising at speed. Pilot screws are set at 2 1/2 turns up or close, I forget exactly but it is close. Up for more air to smooth it out?   Would it be wise to use a hotter spark plug than stock since it has been bored out. Like I said, the bike runs great under power. I would just like to smooth it out on the cruising side of things.
Thanks for the help

I would not use a hotter plug.  If anything, colder may be in order.

The pilot screw only has a small effect on the mixture, mostly at idle and just off.  You can try different settings, but I doubt you will see significant differences.

thanks for the response. but what do you think is causing the feeling of the bike surging when I try to maintain an even speed? I have gone up twice on the pilot jet and there are 3 washers under the needle. I started with two and didn't feel it was right. Went down to one and it was worse. Went to three and as I said the bike runs great under power. Its just that it doesn't want to cruise smoothly. 

Can you fit another washer or two under the needles? If one is no good and 3 are better, 5 might do the trick. I sometimes cut small sections of weed trimmer fuel line to slip over the needles. It is easer than dealing with all those washers. 

thanks for your response. I'm not sure that's the answer though. It runs great under power but looking at the spark plugs I can see that it is a little too rich now. Giving it more gas I think will not help. Two washers not enough, three plenty. I think.  I'm thinking it needs more air. I don't know. What is this surging and failure to run smoothly?

That suggests lean running at speed. 

Surging can be caused by a lean mixture . Improvement by raising the needles also suggests a lean mixture. Three washers suggests there is a problem elsewhere.
Are the carb holders old, hard and maybe starting to have surface cracks?
Are the carbs not fully seated in the carb holders?
Wrong needles or jets?
correct fuel level confirmed by the clear tube method?
Cheap pod filters blocking the air corrector jets?

thanks for the replies. 

but..........   carb holders are new, as is almost every thing on this engine. I know the carbs are also seated properly. Looking at the spark plug indicates a slightly rich mixture. The electrode is almost the brown color it should be but the base of the plug is black. That seems to indicate a mixture that is a little too rich. Unburned fuel is what I'm being told.  Maybe I shouldn't have gone two up on the pilot jets?

Are the valve guide seals new? If not they could lead you to believe it's rich when it's running lean. The surging is the tip off but diaphragms could also be the culprit. Have you tried the thumb test on the slides?

If it surging at steady throttle it is often lean. Have you tried to give it a little choke when surging if it runs better it is lean for sure.What is rpm at when surging?

all valve guides are new and the valves have been professionally seated. Not sure what you mean by the thumb test on the slides.

thanks for the reply.

It surges at anytime I try to keep a steady speed.