90106-ZW1-003 Oil Check Bolt - Overview. The 90106-ZW1-003 Oil Check Bolt is an essential component in Honda marine engine systems, specifically designed to support the oil check system in Honda outboard engines. This bolt plays a critical role in maintaining accurate oil level readings, ensuring your engine runs smoothly and reliably. Manufactured to meet factory specifications, it integrates seamlessly with existing parts to maintain optimal performance and durability.. Key Features. Genuine O