Rope clog-

[ScarabMike]

Ive done it on my boat. As long as you don't gun the throttle, you will be ok. But yes, its a recipe for a new exhaust.

@ScarabMike ah....got it! Basically, the ride plate is the heat exchanger! (took me a while! LOL) I still think reving an engine with a clogged pump is a recipe for a melt down of the exhaust. I'll bet if you do that for more than about 3-4 minutes something will melt....

 

[funbobby]

Was I wrong to turn that engine off and limp back on a single? I have to get the boat to the landing tomorrow, which is 4-5 miles away..

@Owen87 - did you pinch the exhaust manifold water outlet hose on the non-running engine and stay below 15 MPH? See manual excerpt below.

 

[0wen87]

I did stay below 15, but I forgot my hose pincher when I left the dock!! When I read that, I thought that the manual covered different models, since the Rotax is a "closed loop" ... I guess I'm learning the hard way!

 

[funbobby]

I did stay below 15, but I forgot my hose pincher when I left the dock!! When I read that, I thought that the manual covered different models, since the Rotax is a "closed loop" ... I guess I'm learning the hard way!

I was surprised to read that too, but I guess if the exhaust fills up and there's no exhaust pressure to expel it, then the water can still get into the engine somehow. At least that's what the manual says.

 

[ScarabMike]

You will be fine @0wen87 That manual takes some info from the regular uncatalyzed engines. Though it may still happen, and its recommended to pinch the hose..... Our engines have huge catalytic converters that the water has to get through before the water makes it to the engine. Plus the water box is baffled to prevent intrusion.

Im not saying not to pinch the hose and follow proper procedure, just letting you know you will be fine.

 

[Julian]

@0wen87 do you have a photo of the hole you are seeing? Does it look melted?

 

[ScarabMike]

When the exhaust melts, its not the metal parts that actually melt, its the exhaust hoses due to the heat from the metal, and sensors connected to them. See pic of a melted rotax water box, you can see the hose in liquid form. The hole probably came from something else.

@0wen87 do you have a photo of the hole you are seeing? Does it look melted?

 

[0wen87]

Mechanic said the water-box did have a hole in it. He replaced that, but still has an exhaust sound/leak in the engine compartment. He has checked all of the hoses and clamps but hasn't found anything....

 

[ScarabMike]

@0wen87 You may have a leak on the exhaust manifold. The only way I would know how to search for the leak is to use an open ended stethoscope. Can you see fumes still, or just sound.

I don't know about you, but for a hole to be opened in the water box, it looks like the boat or engine took an extremely hard hit. Have them check engine/driveshaft alignment. It can lead to premature wear on the carbon seal, and can sink your boat. It happened to @Slugger55 .

 

[0wen87]

The hole was opened from the INSIDE of the water box! No impact what so ever...

 

[ScarabMike]

wow thats crazy.

 

[0wen87]

CORRECTION: It is the muffler, not technically the water box..

 

[0wen87]

Here is the problem (or the result of the problem). How this happened I have no idea!

 

[Julian]

Dealer should replace that whole part!

 

[Yan Masse]

Here is the problem (or the result of the problem). How this happened I have no idea!

How can this happen!?!

 

[0wen87]

Dealer was happy to, but one did not exist from Scarab.. He is searching the country. In the meantime, I'm having it patched

 

[0wen87]

Straight below the exhaust inlet. This is the bottom side, which would be against the hull.

 

[itsdgm]

It looks like that's directly below the exhaust inlet. Was cooling water supply compromised? If so, it's possible that the box overheated. Also, I'd imagine that there's a rubber pad that protects the box where it sits in the hull. How did that piece look? Or was it there?

 

[Scarabtech]

here's a couple of service manual pics. Unfortunately they don't give a good waterflow diagram on the intercooler side. When a ski rope gets wrapped up that bad it can rip the shafts guard down due to the rope going straight down thru the intake grate. Running the engine after sacking up a ski rope is the worst thing you can do the impeller and driveshaft only spin in one direction.

 

[ScarabMike]

@Scarabtech That is the coolant flow and system. The exhaust does use raw water that is shared with the intercooler. I cant help but ask if you are truly a tech, your misinformation is the reason these boats are failing fast. Where did you get your training?