MK 11 exhaust hose

[cmainprize]

When inspecting the section of exhaust hose from the riser to the muffler I discover the wire reinforcement inside the hose had broken and the hose had delaminated and was very close to failure.  Visually the hose appeared normal, give it a squeeze to test.

I have never liked the Hardwall hose used between the riser and the muffler.  It is very hard to work with, and the distance from the riser to the muffler on the MK11's is very close and requires a very hard bend.  This type of hose also transmits alot of the engine vibration to the muffler.  

My solution was to use Silicone hose and a fiberglass elbow to reduce vibration and make a fair hose run.  No one had the fiberglass elbow in stock and my local stainless guy was super busy so I made the elbow with standard fiberglass and epoxy.  I will be able to test it in a few weeks when we go back in the water.  Picture attached.

[SeaFever]

Cory,

I am surprised you did not find the FG elbow in local marine shops...perhaps the correct diameter was the challenge. Great work on making one.How did you make it, and get the right diameter while doing that? Did you use a 'form' to wrap FG around? If yes, how did you take the form out when you were done? Just curious.

Nice clean engine room, BTW. What did you use for white paint? I used Rustoleum white enamel bit that looses it shine after a few months. Perhaps I did not apply enough coats...

Cheers.

[cmainprize]

Seafever,
Everyone had 1 1/2, I could not find the 1 5/8 I needed.  I made the elbow by wrapping a straight peice of 1 1/8 dowel with glass and expoy four times after I had waxed the dowl several times.  Pulled the tube off the dowel and cut a 22.5 miter in the middle.  Epoxyed that together and then wrapped it 6 ( I think) until it was 1 5/8 OD.
Picture below.

My engine room is not painted, that's the factory gel coat.  It's actually dirtier then normal because I have been doing some work and have not cleaned up yet.

[SeaFever]

Nice work...

[Roc]

I used Vetus rubber exhaust hose (black with yellow stripes), which is designed to be able to make tight bends.  Page 100-101 in the catalog

http://www.vetusmarine.com/catalog.html

[John Langford]

Roc,
The standard hose is 1 5/8" ID. Do you recall if you bought the Vetus 1 3/4" (45mm) or 1 9/16 (40mm) ID hose and if the smaller, was it hard to get it on?

[Roc]

John,
I checked and I used the 40mm ID size.  It's been several years since I installed the hose, but I don't recall any issue installing it. I probably lubed it up with dishwashing soap to help it slip on.  I also double clamped it with the hose clamps with "rolled" edges.  The flexibilty is great.  As you know, with our M35B engine, the exhaust hose makes a close to 90 degree bend to the muffler.  This Vetus hose makes the turn with no problem.  I think anyone with the orginal OEM hose, should switch it out with this hose because of it's flexibility, and in my mind, decreases any force imparted to the fiberglass input on the muffler.

[John Langford]

Thanks Roc. It's on my short list. I can feel a leaking muffler in my future if I don't.

Thanks for the suggestion.