Riser problems

[Regalrob99]

I took my 99 Regal with a 5.0 Volvo Penta out for the first time since de-win. Boat ran fine for about an hour and then heard a loud bang and started smoking. Blew a hole in the rubber boot that connects the riser to the exhaust pipe. Temp gage never went above 125. Not sure what could have caused this?

 

[alldodge]

That is some bad luck. You had a backfire large enough to blow a boot apart.

Assuming not a new to you boat, but how did it do last season?
What is the model number of the motor?