1. Examine the crankcase for cracks and damage to the gasket surfaces. Replace, if necessary.
2. Inspect the studs in the crankcase, if used. Replace any bent or damaged studs.
3. On bottom lubricated crankcases the oil passage must be thoroughly cleaned to ensure oil flow.
4. Clean all gasket surfaces. Ensure that all gasket surfaces are free of nicks, scratches and burrs that would affect a good gasket seal. Replace, as required.