Regarding the engine, the 94mm flat-top now had 10,000 miles on it (actually 12,250 miles if you consider the 2250 miles I logged on the first build). It was running well. Power was great, vibration normal, temperatures normal (180 oil/280 CHT), oil pressure normal (7psi @ 4000 rpm with 200°F oil temp), fuel economy excellent, and oil consumption the same (about 8 ounces every 1100 miles).
But noise levels were up significantly, and the clutch was getting real grabby and unpredictable.
At around 8500 miles, it started rattling. I thought it might be developing some piston slap. After all, the cylinder had been honed several times for various projects, and I lean toward the loose side on forged pistons. But by the 10,000-mile mark that sucker was making a loud metallic rattle. The rattle was most pronounced when I throttled up in neutral. This was more than just some minor piston slap. I needed to address the noise immediately. This YouTube vid tells the story.
https://www.youtube.com/shorts/KUhN_OHQhmoThe clutch noise (squeal) I reported at the 7000-mile inspection was now louder. And as I mentioned, the clutch was starting to get grabby and unpredictable. I could live with it, but the average bear wouldn’t like the lack of a smooth progressive engagement. Time to take a look.