rattle noise in risers?

[Frankiea87]

hey guys i have a 1988 sea ray sundancer 260 with a 454 v8 7.4l mercruiser with alpha drive... i have a wierd rattle noise comming from/sounds like around the risers/manifolds near the transom. anyone know what this could be? thanks.

 

[Bt Doctur]

Re: rattle noise in risers?

possable exaust flappers in the exaust pipe
http://www.boatfix.com/merc/Servmanl/16/16D7R2.PDF

 

[Frankiea87]

Re: rattle noise in risers?

yea thats what few guys at the docks said.. but not sure.. is it a bad thing? normal?

 

[Bt Doctur]

Re: rattle noise in risers?

Without an inspection ,who knows. But if they do break loose they can block the exaust and lead to overheating issues.

 

[180shabah]

Re: rattle noise in risers?

Pretty common, water pump not serviced regularly, low water flow, exhaust temp rises, shutters rattle. Let it get hot again and you could be fishing one out of the drive after limping back to the dock due to clogged exhaust.