exhaust shutters/flappers question

[lukeb83]

hey guys. i have an 86 140hp 3.0 liter with an alpha 1. im waiting on some new exhaust shutters to come in the mail but want to fire up the motor to test the impeller job i just did. will running the motor with muffs damage anything without the exhaust shutters in place? thanks guys.

 

[nola mike]

Re: exhaust shutters/flappers question

No, fire 'er up...

 

[lukeb83]

Re: exhaust shutters/flappers question

thanks. im really curious as to what they do. stop backflow? ive heard they arent even necessary. im putting new ones in, but is that true?

 

[Mischief Managed]

Re: exhaust shutters/flappers question

They just prevent water from coming up to the exhaust manifold, if you slow down quickly. They are cheap insurance in case you ever have to make a panic stop and I recommend using them, but also recommend slowing gradually rather than abruptly if at all possible.

 

[dubs283]

Re: exhaust shutters/flappers question

thanks. im really curious as to what they do. stop backflow? ive heard they arent even necessary.

they install them for a reason, as stated to prevent sea water from flowing backwards through the exhaust and through the manifold(s) and possibly hydrolocking the engine

it happens with excessive wave action at the rear of the boat, or stopping quickly and the wake wash pushing into the back of the boat and up the exhaust system

cheap insurance against having to get a tow on the water, in the event of an overheat it is likely the shutters get damaged and need replacing