Speedster 200 Bad throttle cables and exhaust popped off what the????

[gtoimpulse]

I took my boat out today it was running fine and then while towing a tube with my 110 lb son I heard a loud noise both engines stayed running but moving the throttles wouldn't do anything. Boat eventually stalled out and I was towed back in. When I got home, I noticed the cables were very loose from the lever side but I was able to start the port engine run water through the exhaust and it sounded fine. I then started the starboard and it was extremely loud. I noticed the metal exhaust pipe had come loose where the clamp was, but the engine seemed to run ok.

How could these two problems be related? I am sure I need throttle cables as they have never been replaced, but how could the exhaust pop off? Do you guys think I sucked something through the exhaust and there was too much pressure? The last time I went out, I sucked a branch and a bag in the same side, but I was idling around and saw it at the dock. Also, I had the superchargers sent out to be rebuilt a few months ago and I pulled them off myself and it is definitely possible I didn't tighten the exhaust tight enough.

Any help is greatly appreciated.

 

[Sportster-2001-951C-Stock]

Maybe check the motor mounts and make sure they're not broken? Grab the motor and try rocking it back and forth.

 

[gtoimpulse]

The motor mounts are nice and tight I am sure they are fine.I noticed the exhaust clamp may be broken . It is possible that's the exhaust clamp either broke or came loose and the exhaust pipe moved back about 4 inches. The throttles may have gotten snagged on the exhaust as it moved.
Does anyone know if it is common for the exhaust clamps to break?

 

[Sportster-2001-951C-Stock]

I haven't noticed anyone mentioning their exhaust clamp broke. It might be common but if so I'm not aware of it.

 

[gtoimpulse]

Do you think that the exhaust could have had a blockage that could cause the pressure to blow the clamp? Do you think it's wise to try and clear the system while it is apart?

 

[pwgsx]

I don't see the exhaust blowing the clamp off. Maybe the clamp was not too tight and good loose? Strange thing is happening to mine too, I am leaking exhaust and steam at the clamp area but the clamp is tight. The flex area on the J pipe may be bad .

 

[gtoimpulse]

How do I tell of flex area is bad? I looked at a picture I took about a month ago and the exhaust on the engine that is giving me problems I can see more of the flex part. It may have been lose at that time.

 

[pwgsx]

I don't know, I plan to buy a new J pipe. I know its not suppose to be showing that much. Its funny you mention that bc the one that is giving my issues had a ton of the flex area showing which is not good so I re-aligned the pipe and I thought it was ok. Post a pic.

 

[gtoimpulse]

It looks like the clamp broke, and either the hot air from the exhaust or the hot metal piece of the clamp that I can't find melted the intake for the other engine. Now I know things get corroded, and break, but from the look of the clamp it looks like it was burnt a little where it broke. Maybe there was a blockage in the system that heated it up to the point of failure. I am going to look in the exhaust for anything that may be blocking. Does that make sense to do?

 

[pwgsx]

I don't see a blockage in the exhaust unless a baffle in the water box broke off. I would think your temp alarm would have went off if it got that hot. You might have a restriction in your water line, maybe one is fine and the other is blocked. Very strange.

 

[Sportster-2001-951C-Stock]

I think if you had an exhaust blockage you would notice a large difference in performance. A water cooling blockage might cause gasket failures though, and overheating of exhaust components.

 

[gtoimpulse]

Now I am wondering if I had performance issues. I hadn't been out since early August pulling the tube, but it seemed a bit less lively than it's normal neck snapping self. The engines did sound consistent though. The right engine (where the exhaust clamp broke) has been about 500rpms higher for a while according to the tach. I didn't notice any lights and there were no warning beeps.

Can I take a shop vac or a hose to suck out or blow the exhaust tube out from the elbow to the back of the boat? Would it hurt anything? I may stick a camera on a snake in there too see if anything is stuck in there.

I attached a few pictures.

 

[gtoimpulse]

Take a look at the below picture which was taken in August. Notice the left exhaust elbow isn't as tight as the right one. It may have been not put on right or failing at that time.

 

[pwgsx]

Looks like the clamp broke right at the spot welds. I can see the difference in the spacing too, mine looks way worse. I think a new clamp and you should be good to go. Might need a new J pipe but I would try shimming the waterbox first to make it line up better.

 

[Sportster-2001-951C-Stock]

I'd be surprised if you find anything blocking the exhaust but while you have it apart I think it'd be an excellent idea to "duct tape" your shop vac to the outlet and go inside to get an idea of how well air moves through it.

This subject reminds me of the rubber flapper check valves in Mercruiser exhausts that sometimes come lose and flop around. Those were there to stop a following sea from filling the exhaust manifold with water. Still, I haven't seen where one of those coming lose caused enough back pressure to notice.

Now if your clamp broke at the spot welds then that might be b/c it was tightened beyond designed torque spec or vibration simply got to it. These exhaust systems are quite good at vibrating lose so use lock-tite blue as/where the factory service manual specifies and tighten fasteners to the torque values given.

Also, check to make sure all of your pipe support brackets are in place and the rubber grommets are in good condition. I found one completely missing on my boat (unfortunately not lying in the bilge with bolts either, ugh!) and the other bracket was lose as a goose.

 

[gtoimpulse]

Good stuff Sportster 2001. I will do just that. I better get a shop manual. Thanks.