Hi.
Mine has 18 liters (4 3/4 gallons) on it. Still very good compression and no wear on the crank and conrod. BUT: I just got new bearings from AVID today. I can drag and push the flywheel too mush in and out (yes, the flywheel are mounted correct

) and a little side play from the front bearing.
Will report back, when I have changed them and run the engine again
EDIT: Made a meassurement on the crank "pin???": Still 4,99 - 5,00 mm horisontal and 4,98 - 4,99 mm vertical. If the P/S should wear out, it should still be cost efficient to buy a new P/S set. But no need for that right now