Shutters on newer motors

[agallant80]

Do the newer mercruiser motors have exhaust shutters?

 

[Bondo]

Re: Shutters on newer motors

Yes...

 

[agallant80]

Re: Shutters on newer motors

I don't really know anyting about this part of the motor, what do they do, what happens when they go, how hard are they to replace etc. Can someone catch me up?

 

[tpenfield]

Re: Shutters on newer motors

When you slow down and the wake collapses around the stern of the boat, it creates pressure that can cause the sea water (lake water) to go back up the exhaust. this could lead to a hydrolock, and all that fun stuff.. The shutters prevent/reduce the backflow of water

Keep in mind that this situation is when the engine has been backed down, so it is at idling speeds and the exhaust pressure is at fairly low levels, so the water pressure has a fighting chance to work its way back up the exhaust. The hieght of the exhaust is pretty low verusus the water line, so it does not take too much to cause a reverse flow.

I'll be replacing my shutters soon, so you are welcome to come by and watch . .. maybe I'll just post some pictures.

BTW - don't you have a brandy new boat?

 

[agallant80]

Re: Shutters on newer motors

That helps. I do have a brand spankin new boat with 8 hours on it. With that said I am an Engineer and it drives me crazy if I don't understand how something works or what something does. When I was a kid by father came out of his bedroom ready to go to work at 5:am to find me at the kitchen table with his pager taken apart.

To avoid the water backflowing if you just slow down slowly instead of putting it in to neutral will it help avoid the water flowing back in?

 

[MarkSee]

Re: Shutters on newer motors

To avoid the water backflowing if you just slow down slowly instead of putting it in to neutral will it help avoid the water flowing back in?

Absolutely

Mark

 

[Hoosmatroos]

Re: Shutters on newer motors

Sometimes you see that people make a turn while stopping. The wake doesn't bounce to the stern then.

 

[Don S]

Re: Shutters on newer motors

Water is not going to backflow into an engine when slowing down with the engine still running. Even at idle, the exhaust will hold the shutter open and push the water (and exhaust) out. The shutters are there for the ones that come in full steam and shut the engine off, or the ones with the boat parked with the stern pointed toward the incoming waves.

 

[Bondo]

Re: Shutters on newer motors

That helps. I do have a brand spankin new boat with 8 hours on it. With that said I am an Engineer and it drives me crazy if I don't understand how something works or what something does. When I was a kid by father came out of his bedroom ready to go to work at 5:am to find me at the kitchen table with his pager taken apart.

To avoid the water backflowing if you just slow down slowly instead of putting it in to neutral will it help avoid the water flowing back in?

Ayuh,.... As was mentioned recently in another thread 'bout Shutters,...

Generally speakin', they live a Long life, 'bout comparable to the bellows, 'n other transom rubber parts,...
But,...
Shutters Die an almost instantaneous death when the motor is run with No water flowin',...
'bout comparable to the Impeller....