Yamaha 25BMH 30HMH Factory Service Manual, Page 246Get this manual
Quality of the image is intentionally reduced!
CRANKSHAFT AND CYLINDER BODY
1 Check: Cylinder inner surface Score mark Repairreplace(use #600 800 grit wet sandpaper) Water jacket Mineral depositsrustcorrosion CleanreplaceCAUTION: Do not scra