89 5.7 OMC Cobra Exhaust Question

[rml]

Greetings to the Board,<br /><br />When I removed my exhaust bellows, I found two exhaust seals that apparently had broken off and dropped into the pipe. I have yet to disconnect the pipe to remove them and am mostly wondering if this is a common problem and what purpose do they serve when in the proper place? During the last two seasons when running at WOT, the engine temp would soar and then bang and then stall. Now having found these two flappers, I'm wondering is it possible that they could have blocked the exhaust -- a la the old potato on the tailpipe trick -- and caused the overheating/banging/stalling?<br /><br />Regards,<br /><br /> --rml

 

[motox6]

Re: 89 5.7 OMC Cobra Exhaust Question

Are you refering to 2 rubber type flappers in each exhaust pipe? If so, those are basically there to prevent water from backing up into your exhaust manifolds while in reverse or id big waves hit the back of your boat while anchored. At the top of the pipes before the booted pipe, there should be pins going thru the pipe with a rubber bushing on each side. When they get too hot they will melt into a big glob. Its possible they could get stuck like a potato and stall the engine. These flappers should open and close freely.

 

[rml]

Re: 89 5.7 OMC Cobra Exhaust Question

Thanks motox6, so they do in fact have a purpose...I took the exhaust pipes apart and low and behold - no flappers -- just the pins and bushings.<br /><br /> --rml

 

[motox6]

Re: 89 5.7 OMC Cobra Exhaust Question

You're welcome, i just found out about those myself, real easy to install too.

 

[rml]

Re: 89 5.7 OMC Cobra Exhaust Question

Easy install, but in my case the old ones didn't melt, they're just sitting in there -- too big to pull through the exhaust bellows flange, not secure enough to hack saw/break up. I tried to shove a vacuum hose down the pipe to try and snag 'em -- no luck. Any ideas on how to get 'em out?<br /><br /> --rml

 

[motox6]

Re: 89 5.7 OMC Cobra Exhaust Question

Try mechaincal fingers, maybe before that use a heat gun to loosen them up and possibly melt them a little bit.

 

[rml]

Re: 89 5.7 OMC Cobra Exhaust Question

Thanks again motox6, I ended up wedging them in the outlet and snapping them in half with a 6' pry bar. Out they came.<br /><br />Regards,<br /><br /> --rml