Why did engine shut off when exhaust cone came loose?

[gtbuzzzz]

I was on a ride with my 2001 GTI (717 single carb) when I hear a loud whizzing/vibration noise. I let off the throttle, slow down and apply the throttle again. I hear the whiz and let off the throttle and the engine cut off. I restart the ski and give it throttle, but hear the whiz again and again it shuts off. I lift the seat and see smoke coming out. I take a few minutes to access the situation and notice that the exhaust cone has come loose from the main exhaust pipe. I grab my tool kit and proceed to reconnect the two parts via the clamps and coupling. Took about 35 minutes but got it back on. I was able to start the ski back up and it was up and running just fine. I'm trying to understand what happened here. I was thinking this would have simply caused exhaust to fill the hull vs go out the back, but instead it made a crazy noise and shut the engine off. Is this some sort of safety mechanism? Any thoughts on the mechanics of this would be much appreciated. Still learning how this machine ticks.

Thank you all,

GTA

 

[azsxr]

No 02

 

[2strokeboy]

So the whiz was either the exhaust coming out of the small hole or just the engine noise and it shut off cause engines need oxygen and exhaust fumes don't have oxygen.

 

[azsxr]

You got it

 

[gtbuzzzz]

I appreciate the responses. I did not think about the oxygen aspect. So given the exhaust was dumping into the hull, there was no fresh oxygen to run the engine properly. Is that a fair statement? Fortunately, this was an easy fix but certainly good to understand what was going on. Thx again all.

 

[mikidymac]

Yes, the exhaust chokes out combustion.