J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Engine Compartment vents at stern

Ryan - I don't think the venting is critical for engine operation, because the space is not air tight, however...

The engine compartment should get some sort of ventilation to prolong engine life and remove the heat generated there. The engine intake consumes air in that space for engine combustion, and cooler air on the intake helps it run more efficiently. Also, if there are any fumes (e.g. exhaust leak, crankcase oil fumes, etc. you could create an unsafe condition below when motoring. Bottom line - the Yanmar won't stop operating if the space isn't vented, but it's safer to vent and in the long run, your Yanmar will feel better!