Super Jet Symptoms of exhaust manifold leak? or air leak?

[rossthaboss11]

Ive got a 760 superjet with all the goodies. Ski was running perfect and then it started acting funny. It is hesitant in lower/mid rpm's and doesnt have the punch or throttle response it should. It still rips pretty much normal at top end. It also started dieing at idle and wouldnt even idle very long on the trailer before shuting off. I noticed an exhaust manifold bolt came lose on the bottom left when looking straight at the manifold.

Could that one loose bolt cause these symptoms? Either air or water could be getting in/out through that spot. I pulled the manifold and its hard to tell since the gasket wasnt blown out at that spot. I am going to replace the gasket and re threaded that bolt hole but don't know if thats the answer. Could this be an airleak?

 

[element3488]

Sounds like an exhaust leak where at slow speeds the gasses would choke out the motor. and air leak would run away from you.

 

[JetManiac]

Exhaust leak especially an intermitent one can cause those symptoms. Run with hood cracked open or off(close to shore) to test.

 

[rossthaboss11]

ok thanks guys. thought that was it but just wanted to be sure before throwing it all together.