Replacing Cooked Exhaust Hoses

[pi_r]

ok, maybe I shouldn't ask silly question, but on an omc 5.7 exhaust, like the one in the attached picture (if I attached it correctly), does anyone know why the 2 exhaust hoses (items 3 and 54) separated by a rigid pipe (item 2)? Something to radiate a little more heat that a rubber hose might? A change in diameter to make the water flow more turbulent? or??

Has anyone ever replaced this with a single hose? I didn't measure it yet, but it appears that the riser and y-pipe might be the same od?

 

[HT32BSX115]

Re: Replacing Cooked Exhaust Hoses

Howdy,

Several things can reduce the water flow enough to make the exhaust hoses burn up.

First and foremost is a failed raw water pump. Any number of other things (debris or pieces of previously failed impellers) in the raw water circuit can reduce or obstruct water flow either in the raw water supply or the raw water discharge area like the exhaust manifolds and/or risers completely blocked by rust.

 

[pi_r]

Re: Replacing Cooked Exhaust Hoses

Thanks for the reply, but the reason the hoses cooked is not a mystery, water pump impeller in the lower unit ate itself, and some idiot (me) didn't notice the pegged temp gauge for a few minutes. Replaced the impeller, pumps water like crazy now, and will be ordering the rubber exhaust hoses that go between the riser and the Y-Pipe (ordering new flappers as well, and trying to dig the old ones out of the y-pipe :S ). I was trying to figure out the reason for the steel portion of exhaust pipe between the 2 rubber sections, and why not just run one hose, since it looks like the riser fitting and the y-pipe might have the same od.

 

[HT32BSX115]

Re: Replacing Cooked Exhaust Hoses

I can't see a reason not to......I have never had a boat with "LOG" type manifolds. If the (riser/y-pipe) diameters are the same, I don't see why you couldn't use hose.

 

[jpwdesigns]

Re: Replacing Cooked Exhaust Hoses

Pi_r, i've got a 4.3L with similar pipe hose setup. Was thinking the same thing. Did you try it? I saw these hoses as an option:
http://bpi.ebasicpower.com/mm5/apps/hoses/?p=hS&Product_Code=MPI250-3120&ccode=ALL2R6
http://bpi.ebasicpower.com/pc/MPI252-3120/ALL2R7
http://bpi.ebasicpower.com/pc/MPI200-3120/ALL2R5

I don't really know which one would be best. Hard wall, soft wall, or corregated. I'm guessing soft wall would be easiest to work with.

What did you end up doing?

 

[pi_r]

Re: Replacing Cooked Exhaust Hoses

Thanks. I was looking at soft wall cooling system hose at NAPA but it was too expensive to experiment with. I'm gonna try it it with the soft-wall link you sent.

I still need to find a way to dig the flappers out of the y-pipe, so I haven't fixed yet.

At $12/ft I think it's worth a try.

Thanks again.