I ended up doing the 70cc kit at about 11,000 kms. Mine was beginning to lose compression at that point. It still ran ok, just wasn't quite as fast. It was difficult to start sometimes, and it died on me a few times while running also. When I pulled it apart there was a small amount of scoring inside the cylinder. I also replace the voltage regulator and resistors and fuel petcock at the same time. My oil pump was leaking a little so I just bypassed it and am running premix on the new improved setup. I would think you are probably getting close, but it all depends on how you run it and how much oil it is getting. I tend to run pretty hard and i don't really trust the oil pump. It seems like most major problem on these occur from faulty oil pumps.
