Bellows replacement questions

[lukeb83]

hey guys. i have a 1986 larson 18' with a 3.0 liter 140hp mercruiser with an alpha one outdrive. i have just replaced the impeller assembly and water pocket (they were melted) and noticed my exhaust bellows is burnt out. i mean, it looks like it had caught fire, its that bad. the boat overheated the last time i tok it out. it did not even peg hot on the gauge or smoke or anything so i didnt figure it was this bad. my question is, is it typical for an exhaust bellows to do this? and finally, do i have to remove the gimbal housing to replace the bellows? it appears to just be the section from the rear of the transom to the outdrive. thanks guys.

 

[dubs283]

Re: Bellows replacement questions

do i have to remove the gimbal housing to replace the bellows?

no

it is easier if you remove the bell housing, but not required to change the exhaust bellows

and, yes - in severe overheat cases the exhaust bellows will melt, along with the exhaust boots in the engine compartment, wires, etc...

you may want to test your temp sender/guage if it wasn't reading hot - keep in mind the sender will not read air temp either, it needs to be immersed in water to work properly

 

[Don S]

Re: Bellows replacement questions

Yes, it's normal to burn up rubber parts with all that hot exhaust without water in it to cool it.
If it got hot enough to melt the bellows, pump housing, and water pocket cover, you should also check the exhaust elbow gasket, it will be damaged for sure and could leak water into your engine. Also look at the 2 rubber hoses between the elbow and the exhaust tube, along with the exhaust shutters. They will be burned up too.

 

[lukeb83]

Re: Bellows replacement questions

thanks again guys. don, where can i locate the exhaust elbow gasket? is it likely that i did serious damage to my motor? i appreciate the input.

 

[dubs283]

Re: Bellows replacement questions

where can i locate the exhaust elbow gasket? is it likely that i did serious damage to my motor?.

local mercruiser dealer/repair shop can get you all the OEM parts you need, otherwise you can order aftermarket here on iboats

a compression test will be your first step in checking any internal engine damage due to overheat