looking for help on 185s

[honda83]

I am a new trike rider, 185s, and wanting to learn more. My carb looks okay, the bike doesn't smoke, runs and idles good. However, the plug shows its fouled with a combined gas and oil smell. By screwing my pilot screw in or out does that have anything to do with the rich and lean fuel mixture?
I thought it may have something to do with the oil and was also going to change it, it looks old. What kind of oil would you recommend?

Thanks for the help.

[Somekindofjerk]

Run 10/40... As for the lean/rich. that would be your needle on the slider more or less. Bump it up a notch by first removing the spring then pushing the needle out. There will be a retainer clip that comes out DO NOT LOSE IT!!!! The little c clip comes off pretty easy with a screwdriver handle DO NOT LOSE THIS EITHER!!! Bump the clip up a notch and put it all back together.