Help , smoke signals

pulled a plug does not look good , could this be a valve , valve guide , exhaust valve stem , bike runs strong does not seem to have any power loss , would a heavier oil 20x50 help my smoking problem , i tried putting a piece of nicorette in the tank , but that didn't seem to help , any ideas ?

Hi. So the bike smokes when it runs? Yeah, could be worn valve guides. Haven't looked to see if these bikes use rubber seals on them, if so, could be that too, OR the piston rings are worn.

I'll also say this... unless your bike looks like a mosquito fogger when you ride, there isn't much harm in a bit of smoke in my opinion. It's not like modern engines that have pollution control crap that it will clog. You'll burn more oil and have to clean your plugs a bit more often, but that's about the worst of it. I'm just saying this because I've rebuilt engines for similar problems and regretted waiting until the problem was more than a nuisance.

Oh... maybe there are emission controls in your state though. Hadn't thought about that.

Cheers!

I don't know what kind of kz you're riding (helps if you put your bike info in your signature line) but I know that my 77 650 has rubber valve seals, if those are worn and need replaced they'd sure cause your smoking problem.