Interesting Situation - Exhaust Coupler blowout, engine revs easier

[YUOnDaGround]

1997 Challenger 1800
Twin 787 Rotax

It has been standard operation that my port side engine has a tendency to just cut out when applying the throttle around 3K RPMS. More specifically, I have to ease it up to about 3K then just do a double pump action of the throttle to get it past 3.5k. If I just push it on past the engine will die. I have went through the carbs and even tried a different set of carbs on that engine...does the same thing.

I say that to say this. Today I went out for the first time this season and the same situation with the throttle, no big deal just annoying. Except about 10 min into the ride the exhaust coupler blows out because the water feed line to the second half of the exhaust system that is fed through the pressure regulator on the muffler was pinched. I did not notice this at first, just the extra loud exhaust note and the fact that I did not have to double pump the throttle to get past 3k and it actually rev'd easier. What do you make of this? Something in the pressure regulator? Thanks for your help.

The pictures below just show the actual part on my boat and where they are in the IBP, thought it might help.

 

[YUOnDaGround]

Any ideas before I start playing SwapTronics?

 

[Albysure]

I would put the plug in it and fill the back hull with water...don't go all crazy with water...u wanna keep it lower then carb and other basic parts...I did this and let it sit for a little, came out and noticed that the rubber gaskets around my exhaust was leaking. I replaced them and now I only have about a cup of water or so compared to 5 gallons..it might help you if u try this or u might need the boat running to see leak..u could also leave it on trailer back it down in water and let it run to see where water is coming in...again this might work or might be a little more complex leak, I got lucky with a easy fix...hope this helped some what..

 

[YUOnDaGround]

I have to be honest, I don't know what your solution refers to about my problem? Please clarify.

 

[Albysure]

sorry, i have know idea how it got posted on here. Was for another thread..

 

[YUOnDaGround]

Well I ordered the Pressure Regulator to see if that helps the cut out problem at 3K RPM's. I'll update next time I am on the water.

 

[Blue in Yarmouth]

Have you been back on the water yet? I'd be interested in hearing how you made out.

 

[YUOnDaGround]

Yes, I just had it out last Sunday for a shake down run and it ran great. The stumble that I normally had on the starboard engine at 3k went away and I have a great running boat, it actually ran a little smoother too.