The carbon buildup you show is pretty common for these motors. I’ve had a few of the K motors apart, very simple design. You probably don’t need to remove the cylinder to clean up the carbon, it’s all there for you to see. TherE usually isn’t much In the head area, at least not in mine. But the area under the powerhead that Lab showed is an important area to clean. I had one so clogged it wouldn’t run without the exhaust relief open.
Here’s a picture of my K-80 apart and going back together to give you an idea of how simple they are. The cylinder base gasket is nothing fancy, just very thing gasket material available at good auto parts store. Cut to fit yourself. Good luck. Fun motors.
