Water coming from my I\O Mercruiser exhaust!?

Question

I have a Mercruiser I\O V-8 Ford with a 233 mercruiser unit. When I hook the garden hose up to it and start the engine I have water coming out of the prop. Is this normal? Could it be a riser or shutter?

Answer 1

As you've figured out by now, that is where the cooling water is exhausted from the engine..... I hope this helps, Good luck!

Answer 2

Yes it's normal and you shouldn't turn the water on till the engine is running as some manifolds without risers could allow the water to enter the exhaust and then you have issues>

Answer 3

I take it you are new to I/O's.

There absolutely should be water comming out of the exhaust system for a regular I/O exhaust system during operation.  If you don't see water comming out of the prop or backpressure exhaust ports at the bottom of the transom mount, that's when to be concerned and shut it down immediately.

As with most marine engines, the exhaust requires water to flow through it to cool it from getting excessively hot.  Unlike a vehicle which can disperse this heat in the air with automotive exhaust, a boat must rid of this heat into the water or cause damage to the engine, drive components, or even the boat hull.

However, some I/O's have the exhaust go through transom exhaust ports.

Answer 4

yes, this is normal. the exhaust and cooling water exit via the centre of the propeller