I think the biggest mistake made with newcommers to 4 strokes is NOT CHECKING VALVE SETTINGS. I've seen new engines right out of the box with missadjusted valve clearances. Check before operating the first time and then again after the first half hour of break in. After that, just checking once or twice a year is adequate in most cases. If you see a change in power output or ease of starting, it may also be time to recheck valve clearances. Read and heed the manufacturers instruction sheet.