Melting exhaust hose

[Vintage Eliminator 21]

Just bought a 72 Eliminator Day Cruiser for a project boat. The guy I bought it from said the motor had about 10hrs on it. When we tested on the lake, it seemed to run ok. When we went back to shore, the rubber hose from the right side riser to the outlet on the transome blew a hole it it. These look to be new hoses and are for marine use. I put a new hose on and have put about 2 hrs (not hard running, just cruising) and itÂ’s about to blow again. I noticed tonight the left hose is starting to bubble as well.
The pluming goes from the jet (Bayjet?) to a t, to the logs, from the logs to the front of the block, from the thermostat cover to the riser. I checked to see if something was blocking the riser by just blowing in the hose and seemed to be clear.
I’ve thought about putting a 31/2” steel pipe on, but can’t find anything exept the flexable steel exhaust pipe used on a tractor trailer for a temporary solution.
Can anyone give me some ideas on how to keep from replacing hoses every 2 hrs?

[Mr Twister]

Be sure it does not have a thermostat in it. will not work with your set up.

[FryJet]

I would have to say its either some form of blockage or maybe the hoses from the t-stat housing going to the risers arent equal length and starving one side. You're absolutely sure you have the correct exaust hose on it right? I cant think of anything else it could be. Good luck.
F.J.

[Hallett19]

If you want to mask the problem, there is a company called trident that makes real great hoses. They are high temp and come in every size and are mainly for marine applications.
http://www.marisolmarine.com/parts/trident.html
There is a link, from what I remember they come in normal, hot and hot as hell.

[roostwear]

As odd as it sounds, check your timing. If it's retarded, your exhaust temp can be very high.

[miller19j]

I would try running it on the trailer hooked up to a water hose and see if you are getting water out both sides. I run a thermostat in mine with logs and the rubber hose and have had no problems. But my thermostat has a bypass so it always has water going out the exhaust.

[manuel]

I have the Trident silicone hoses but they are expensive, 3 foot piece of glossy blue 4" I.D. was $107. (glossy red was $182.!!) but they are rated at double the temp. of the normal black rubber stuff, they look GREAT though and should be the last set I ever have to buy, I went ahead and got T-bar clamps also, mine came from,
http://www.mesamarine.com/Trident.html#Trident
you can see all the different stuff they make and the prices, besides the timing mentioned above could your mix be too lean on that side ?
Good luck, Manuel

[sidewound]

Sounds like no water in the exhaust to me. I'm probably wrong. I usually am.
I can vouch for the stoutness of the trident hose tho. It's BADASS! Steel reinforced etc! Had a helluva time just gettin it connected cause it was so stiff.
Peace Man :cool:
CESAR

[DansBlown73Nordic]

I would try running it in the water and pull the hoses off the logs and see if any water is coming out. Sounds like you have a plugged hose or something.

[DansBlown73Nordic]

I would try running it in the water and pull the hoses off the logs and see if any water is coming out. Sounds like you have a plugged hose or something.
On my Stevens I have had this happen. I added a 3 in hose inside of the 3 1/2 to make a liner. It has worked great so far.

[Vintage Eliminator 21]

Thanks for all the input. While I was working on it tonight, I found the hose going to the riser from the tstat on the right was 3/4 and the left 5/8. I put new 5/8 on both sides and taking it out early Sat am. We'll see how it responds. Will make sure there's water coming out both sides.

[Vintage Eliminator 21]

On the adivce of a local jet guy who runs a marine repair, I replaced the 5/8 hose (from the tstat housing to risers) and fittings with 3/4. When I tested it today, I checked the risers and the hose to see how hot they were and it was hot to touch, but not so much I couldn't keep my hand on either one. Hopefully, this will work.

[ole war horse]

Dans 66 was right about having the boat in the water running and pulling off hoses to make sure there is water flow and make sure there is good water flow from the pump discharge to the tee that goes into the logs. That thermostat tower set up from Rex marine works great and no proplem running a stat this way to matain correct engine temps.

[Rexone]

If there is proper water flow in the exhaust hoses you should not need any special exhaust hose to mask this problem. Not that good hose isn't a good idea. If you can place your hand on them and leave it there they are nowhere near hot enough to burn through the hose. Of course that may change at higher throttle if you have inadequate water flow. If you need any help just call us at 909-392-7300. :)

[Liberator TJ1984]

That High temp. hose is made out of Silicon and is usually Blue with a red inside layer..
We use it here at work and it is higher but it can be found at Tractor or Over the road Truck parts dealers for alot less than what is in the above post...want to say 4" cost us around 10 to 12 bucks a foot
It works
Gopherrr

[Kachinalazer]

You might want to pop off the little manifolds at the water inlets (where a water pump usually is) as well as the t-stat housing. When I rebuilt my engine and took them off, the hoses were all clear but those little manifolds/fittings were all crusty and the orifices were extremely small. It's like calcification, and you can dig it out fairly easily with a screwdriver. If they're really bad, you might have to question the water jackets in the engine too. On both of my jetboats, you could put your hand on the exhaust hoses all day long, they have enough water running through them that they never got above just warm. I've also noticed that when you first start the boat up, the exhaust note is quite a bit louder until the water gets pumping through the system, and that muffles the exhaust tone a bit. If you don't hear that change, and your hoses are still heating up, you must have blockage somewhere. My hoses are all 5/8 and everything is fine. Hope you find your problem.