Patent ID: 7624713

Claim:
A crankcase for an internal combustion engine, said crankcase comprising a mounting structure for an oil level sight glass for the internal combustion engine, said mounting structure configured to receive an oil level sight glass fitted on an outer portion of the crankcase in a through hole formed in a lower portion of a vertical side wall of the crankcase; an outwardly-protruding rib formed on the vertical side wall of the crankcase; and a retainer member clamped to an outer surface of the vertical side wall to prevent the oil level sight glass from falling off; said retainer member having a cut formed thereon; wherein: the retainer member has a scale mark provided thereon; said cut engages the rib for positioning the retainer member on the outer surface of the vertical wall; and the oil level sight glass permits visual observation for checking an oil level of oil held in an oil reservoir disposed at a lower portion of the crankcase.